Rossweisse is one of the many female protagonists of High School DxD. A former bodyguard for Odin, she is currently acting as the Civics Teacher at Kuoh Academy and Class 3-B's Homeroom Teacher. She was formerly Rias Gremory's second Rook, alongside Koneko Toujou, but now serves as Issei Hyoudou's first Rook.
Rossweisse is a beautiful young woman with long, straight silver hair and aqua colored eyes who appears to be in her late teens. Her body measurements are [B96-W61-H89 cm] [B38-W24-H35 in]; height is 173 cm (5 feet 8 inches) and body weight is [59 kg].
Her battle attire is normally of a set of Valkyrie armor, which consists of a white breastplate with gold and pale blue accents and matching, fingerless gauntlets, boots, hip guards, and wing-shaped hair clips. She also wears a black leotard underneath her breastplate, black thigh-high stockings, and a pale blue cloth wrapped underneath her hip guards, all of which are clad with pink lacing along with her hair clips.
For her teaching position at Kuoh Academy, she wears a simple business suit and skirt. When she is not at work, she is noted for often wearing cheap, plain jerseys. It was pointed out by Euclid that Rossweisse has a strong resemblance to his sister, Grayfia, as both of them have silver hair.
Rossweisse is known to be a very serious person. She has a tendency to buy things at sales when they're cheap, causing Issei to dub her "The 100-Yen Shop Valkyrie". She is extremely bitter and sensitive about not having a boyfriend and is quick to anger when made fun of. Despite her seriousness, she is highly susceptible to alcohol, and one drink from it can leave her drunk and vomiting for extended periods of time. Rossweisse also has a tendency to speak using her country's accent when she is flustered.
Like the other girls, Rossweisse acts like someone her age whenever she is on a date with Issei as she ended up acting shy when she was called cute. She soon develops romantic feelings for Issei in Volume 17 when he proclaimed to her that he will protect her from Euclid, which he did.
After falling in love with Issei and becoming engaged to him, Rossweisse has started to partake in perverted activities she normally frowns upon, such as wanting him to apply suntan oil on her, sleeping with him while wearing revealing lingerie and fighting with the other girls over him.
Rossweisse was raised in the countryside by her grandmother, Göndul, as both her parents are warriors who serve the Norse Gods and rarely come home. While still a child, Rossweisse went through several ceremonies that were meant for her to inherit her family's magical crest, but she wasn't able to inherit it for some reason, and her cousin ended up receiving the position as the family head instead.
As a consequence of trying to make up for her perceived shortcomings in magic, Rossweisse's school life was completely academic, to the point that she did not have a social life and looked down on her classmates that rarely spent any time studying, which contributed to Rossweisse's rapid grade skipping through high-school and college and her degrading nickname, "The Valkyrie that's never had a boyfriend."
While in college, Rossweisse wrote an essay about Trihexa but never published it. Regardless, she is considered to be a sought-after expert on the creature by Qlippoth. At some point before the series, she was appointed as Odin's bodyguard. During her time with Odin, Rossweisse was basically used as a maid by Odin, taking care of him during his trips, supporting Odin with his daily life, despite her small salary, and was even mistreated by her fellow Valkyrie who called her Odin's "Servant Girl".
Rossweisse makes her first appearance in Volume 5 as Odin's bodyguard, reminding him of his status and telling him not to look at Serafall Leviathan lecherously. Odin responds by mocking her for not having a boyfriend, which caused her to break down in tears.
She later reappears in Volume 7 during Issei and Akeno's date, scolding them for being in the motel during the day and telling them that high-school students should stay at home and study. She then accompanies Odin to the Hyoudou Residence, scolding Odin for looking at Rias and Akeno's breasts lecherously before introducing herself to the Occult Research Club and was embarrassed when Odin added the point on her not having a boyfriend. She later helps in the battle against Loki and Fenrir and sealed Loki with her spells. She was abandoned shortly after that by Odin, much to her horror, claiming that she was fired. She was then persuaded by Rias into becoming her servant when she looked at the Gremory summary papers and is amazingly fascinated by the huge amount of money, premium insurance, and connection benefits she will receive by becoming a Devil under her peerage, and having a stable job of becoming a teacher at Kuoh Academy.
In Volume 9, she accompanies the second-year students to Kyoto. When Issei attempted to peek at the girls, Rossweisse attempted to stop him only to become another victim of Issei's Dress Break, much to her horror, due to the fact that her jersey (which was bought while on discount) was ruined. When Issei sees Azazel drinking in the morning and telling him that it is not good for his health, Rossweisse strongly agrees and lectures Azazel on the fact but was cut short after having being teased by Azazel on not having a boyfriend. Angered by that, she snatches his alcohol and drinks all of it, making herself drunk. This action, however, would indirectly cause her loss when she fought against Heracles.
In Volume 10, she and Koneko fought against Misteeta Sabnock and Gandoma Balam at the Rating Game between their masters, winning the match. She, Xenovia, and Yuuto Kiba would then face Sairaorg Bael but lost to the latter.
In Volume 11, Rossweisse goes back to Asgard to train after her defeat in Kyoto and in her match against Sairaorg but reminded Issei of his mid-term test and prepared a question paper for his reference before leaving.
In Volume 12, she returns after learning various defense magic from her homeland, which would allow her to defend against attacks that are 10 times more powerful than Heracles' Balance Breaker. She also told Rias and her comrades about the rumors that she heard in her homeland regarding the Vampires, that a certain noble Vampire house captured a Longinus possessor which lead to battles between Vampires. After Issei successfully passes his Middle-class Promotion test, Rossweisse like all the female members of the Occult Research Club, decided to go out on a date with Issei.
During the events of Volume 14, Rossweisse participated in the meeting of Mephisto Pheles in regards to making a pact with a Magician due to the Gremory group's recent popularity. Later, she participates in the meeting with the Vampires from the Carmilla Faction. She, along with the rest of the Gremory group (excluding Rias and Kiba), later team up with the Sitri group to rescue Ravel, Koneko, and Gasper after the three were taken captive by the Magician Faction.
In Volume 16, Rossweisse, along with the Occult Research Club members, Bennia, and Loup Garou, went to Romania to aid Rias and Yuuto, who were confined in the Tepes castle. On their way to the Tepes' castle, Rossweisse told Issei that she received an offer from Sona Sitri to become a teacher in the Rating Game school that the latter is building. She then participated in the attempt to stop the extraction of the Longinus, Sephiroth Graal, from Valerie Tepes and rescue her; fighting the enhanced Vampires and Grendel along the way. Rossweisse later teamed up with Yuuto to defeat the mass-produced Evil Dragons that were rampaging in the Tepes' castle town. After returning from Romania, she participated in the meeting for the formation of D×D.
In Volume 17, Rossweisse asks Issei to be her boyfriend, as she lied to her grandmother, Göndul, about having one. She later goes on a date with Issei under her grandmother's pressure. Heading to Tokyo, the date ends abruptly due to the sudden appearance of Euclid Lucifuge, who came to try and recruit Rossweisse into Qlippoth. Later on, Rossweisse joins the rest of the Occult Research Club and Student Council as they hold an open house for Sona Sitri's newly build Auros Academy, teaching many of the prospective students magic alongside her grandmother. At night Rossweisse entered the male's bathhouse where she meets up with Issei due to hot water being out in the female's, they have a discussion on her research on Trihexa, worried about being taken and used by the enemy, Rossweise asks Issei to kill her if it were to happen but he refuses to say he will protect her.
Unfortunately, Qlippoth suddenly attacks the school by putting up a huge barrier (also serving as a massive time dilation field where one hour inside becomes one minute outside) around the town and assaulting it with the mass-produced Evil Dragons army as well as Ladon, Azi Dahaka, Grendel, and Walburga. During the battle, Rossweisse served as a bodyguard for Asia, who was flying around the battlefield on Ryuuteimaru, Issei's familiar, to serve as a battlefield medic. At the climax of the battle, Euclid arrives and kidnaps Rossweisse, revealing that due to their loose resemblance, Euclid intends to turn Rossweisse into a replacement for Grayfia, as well as planning to tap into her knowledge of Trihexa's seals to further their goal of unsealing it. In the ensuing battle, Issei is able to overpower Euclid using his Wyverns and newly-acquired Longinus Smasher with Rossweisse using the magical rope Euclid tried to use on her to restrain him. In the end, Rossweise falls in love with Issei and ask him if they can go to a 200 yen shop next time.
Rossweisse and the Occult Research Club went to Heaven in Volume 18 to talk to Michael about the Christmas project the alliance is working on. After the meeting, Michael informed them about the deaths of Church officials and the presence of Evil Dragons found at the attacks. Rossweisse helped defend Heaven from the attack of Qlippoth. She, along with Rias, Koneko, Gasper, Yuuto, Akeno, and Cao Cao, fought against the group consisting of the Evil Dragon Ladon and three Grendel clones. She, Akeno, and Yuuto teamed up to defeat a Grendel clone and used the binding technique Euclid used on her in the Underworld to incapacitate another clone for Akeno to finish off. She is later seen along with the other girls observing the Interdimensional Room that Touji Shidou brought for Irina to be able to have sex with Issei without falling and commented on how her head was full of indecent thoughts and tried to expel them feeling it was too early for her.
In the Extra Life of DX.1, the Gremory Team participated in a rating Game rematch against Riser Phenex. Rossweisse teams up with Gasper and takes down three of Riser's Pawns, they waited at the replica of the main school building where they meet Issei and Asia being escorted by Mihae to her master, as Issei and Asia head to the roof, Rossweisse and Gasper face off against Mihae which the pair manage to win. The victory goes to the Gremory Team as Issei was able to defeat Riser.
In Volume 19, along with other members of D×D, Rossweisse took part in the battle against Church rebellions led by Vasco Strada and Ewald Cristaldi. After Vasco was defeated, Walburga and an army of Evil Dragons ambushed them, however, they gain the advantage when Rossweisse activated a barrier forcing the Dragon army to be immobilized, this action caused Walburga to activate her Balance Breaker that contained half the soul of Yamata no Orochi. however, Walburga was soon defeated and arrested. Along with her friends later heard the news about Ravel went missing during her brother and Diehauser's Rating Game.
In Volume 20, Rossweisse would help prepare students who are going through career consultation. D×D headed to meet with Ajuka who was able to recover Ravel but are told about the shocking truth about his secret creation; the King Pieces. When Issei's parents are kidnapped, D×D infiltrated Qlippoth's hideout on the stolen city Agreas to save them, Gasper uses his Balor form when the Gremory Team battle against the Evil Dragon who took Issei's family; Niðhöggr. All their attacks prove to be ineffective as the Dragon was equipped with several Pheonix Tears vials until Crom Cruach comes in and starts mercilessly beating Niðhöggr.
In Volume 21, when Issei was discharged from the hospital and met up with his friends, worried for his safety, Rossweisse gave him a Nordic talisman she made in the style of a Japanese charm amulet they head off into battle. During the war against Qlippoths army, Rossweisse had completed her 616 sealing spell and manages to cast it on the head of 666 and was able to seal the movement of the main bodies of the legendary beast. The spell, however, was unsuccessful in fully stopping 666 as the beast extract its core before it was fully sealed.
In Volume 22, one of their weekend off, the Occult Research Club, Vali's team and Issei's parents went on a fishing trip on an inhabited island owned by someone related to them. When Xenovia and Irina began a fishing competition, Rossweisse wore a wetsuit and attempted to catch fish by diving into the water with a harpoon.
Rossweisse and all of Issei's friends were present during his ceremony for graduating into a High-Class Devil. After the ceremony when Asia and Xenovia wanted to move to his peerage. When everyone's graduation ceremony had concluded, Rias requested that Rossweisse be also transferred, while Rossweisse was initially baffled by this, Rias hugged her and assured that she believed that Rossweisse will be able to release all of her potential the most by serving under Issei while in turn he will need her strength and support, which she accepted as the two shed tears. Immediately after, Rossweisse was among the ORC members present when Issei proposed to Rias.
Red Dragon Emperor of the Blazing Truth × White Dragon Emperor of the Morning Star: The True Dragon(s) of the Kuoh Academy
Issei's Team arrived fashionably late to the opening ceremony of the Azazel Cup while making a grand entrance by flying down with Ryuuteimaru. Ten days later, after going through the first few matches, their entire team receives bad ratings in the tournament. For their next match up, Rossweisse and her teammates would eventually go up against Baraqiel's team of Fallen Angels under the Rating Game rules Object. Rossweisse used her magic to locate and identify the object they needed to score points. The victor goes to her team when Issei defeated Baraqiel while proposing to Akeno.
In Volume 23, her team had just won another victory. In the waiting room, Rossweisse noted how one of the reasons for their continuing winning streak could be that they haven't faced any God-Class beings yet, for the rest of the time, they discussed how counter measures could be used against them no matter how strong they were. At school, an energetic Rossweisse stood upon the podium, now as the homeroom teacher of the third year’s B class, announced a ball tournament will be happening and that they cannot lose. After school, everyone continued their Devil jobs for a branch store of the Gremory Large Enterprise, Rossweisse's handled summon requests that required magic. She had just come back from a job with an antique clock that had been a decoration as appraisal, she handed it over to Ravel to check its worth with a professional. After Issei's talk with Asia, she and the other girls mistook it for some workplace romance.
Her team then had a meeting with their next opponents; Dulio and his team of Brave Saints at the Hyoudou Residence. Days later within the club room, the team had invited Ouryuu to increase their numbers. Once the matter had been settled, with two Student Council members on their side, Rossweisse felt it best to report back to the Gremory House that supports the school later.
When the time came for their match up against Dulio and his team of Reincarnated Angels, the game was set under the game rules of "Rampage Ball", in which both teams must find the goals that appear all over the game field and then throw the ball in. Before setting out, Rossweisse used her magic to improve everyone's physical abilities. The team then headed after the ball before the others did, they were met with thunderclouds created by Dulio that caused icy cold heavy rain accompanied by lightning strikes that they dodged. After a bit of a scuffle at first, their side had gained the first points. The game goes on for about two hours as both teams scored a roughly even number of points. Rossweisse supported Irina and Xenovia against Kiyotora Shinra and Dulio who had the ball and fired off large bursts of offensive magic at them, but Mirana-san created an extremely large spear of light to easily obliterate her spells. Rossweise was then forced to retreat when Griselda joined the fray with her bow and arrows and fired them at her. In the end, victory goes to Dulio's team with the score being 144 – 146.
When the school's ball tournament had commenced with the Occult Research Club playing Basket Ball against the Student Council, Rossweisse had motivated the ORC members that whether they win or lose, they shouldn't leave behind any regrets. The resulted scores ended in a tie.
In Volume 24, when everyone came to the school pool for an enjoyable time, she watches on as all of Issei's fiancées fought over who should he apply suntan oil to first and claims that she should also get the right as his servant. They head back to the Hyoudou Residence when they hear that the parents and guardians of everyone else have arrived there, they learned the reason for their meeting was to discuss plans for wedding ceremonies for each of Issei's fiancées.
Soon, word came that Kuroka and Koneko were being targeted by Grim Reapers due to being involved in their late father's research in artificially creating Super Devils. When it came time for Rias and Vali's Rating Game match, Rossweisse used her magic to create a barrier over the stadium while every one of her comrades faced an army of Grim Reapers. In the midst of battle, Issei used the tail of his armor to wrap around Rossweisses chest to absorb enough energy for his new technique to use against Thanatos, the resulting effect cause her breasts to temporarily shrink.
Eventually when all their enemies were dealt with, Rossweisse and all her friends went to watch the ending of Rias' match, which they witnessed her having to reluctantly forfeit. Everyone then later payed Rias a visit at the medical room. She watches as almost all of Issei's fiancées requested kisses from Issei as Koneko and Kuroka were hogging him for themselves. A few days later, she and her team were gathered at their homes VIP room by Shemhazai to give them a certain item Azazel had handed to him, Rossweisse was given a Mistilteinn wand. They then met with the others who informed them of Mahabali's loss in the tournament and the opposing sides members; Verrine and Balberith whom they feel a tense pressure from as they claimed to be Super Devils. They began gathering information concerning the new enemies they've met earlier. Just then, Rossweisse received a message from her hometown saying that she'll partake in an arranged marriage with Vidar, news that cries out loud after a slow pause.
In Volume 25, Rossweisse was gathered with the rest of the team in Issei’s room and watched the rival teams achieving their victories. Rosswiesse wasn’t paying attention due to being lost in thought due to her marriage meeting with Vidar. At Kuoh Academy, Rossweisse was in charge of her class’s quiz but she had her mind elsewhere until the female student reminded her that the timer is over. The students started rumors about Rossweisse’s condition and began to spread around the school. As her grandmother Göndul arrives at the Japanese restaurant, Rossweisse argues with her about the marriage meeting with Göndul scolding her about not marrying someone as well raising a family and continued to scold Rossweisse for not allowing Issei to do perverted things to her.
The day of the marriage interview Rossweisse was accompanied by Göndul and Issei for her meeting with Vidar while also dressing formally in a yukata. While waiting in the Japanese-style room, Vidar arrived together with his maids Fulla, Hlin, Gná and they gave Rossweisse, Issei, Göndul a strict expression with Vidar reprimanded them asking to leave things to him. Rossweisse introduces to herself to Vidar as the former personal Valkyrie for Odin and currently a servant of Issei Hyoudou with Göndul and Issei also introduces themselves. Rossweisse and Vidar decided to talk about Odin and considers him a perverted old man that he went to go to all of the girl places and continued to have by bad-mouthing Odin. Rossweisse became astonished by Vidar remarking her as cute and accidentally drank all of Vidar’s beer and in a drunken state asked for five more beers. Rossweisse hugged Issei saying she will be Issei’s wife because he’s a promising Oppai Dragon and very kind to her as well the Underworld is more favorable compared Valhalla. Rossweisse began to cry and continued to say that Issei risked himself to save her from Euclid and became so happy. Rossweisse gets scolded by her senior Brynhildr who was also escorting Vidar for being weak towards alcohol and her intoxication disappears and continues to get scolding from her saying she she mistook Vidar’s beer as her own. Rossweisse and Issei gets shocked about Vidar declaring to get engaged with her and watched as Vidar challenges Issei with Rossweisse on the line.
After the interview, Rossweisse and her team started to analyze the members of Team Leisure of the Kings with her explaining Vidar’s abilities and his mystical boots is what puts him on par Thor. Watching her senior Brynhildr using magic, Rossweisse noted her activation is faster than hers with Grayfia pointing out the magic’s power output is the same and if their activation time and accuracy are better, they’ll lose by numbers. Rossweisse held her legendary weapon Misteltein wand in her hands and revealed to the team she still hasn’t mastered. Rias comes in and tells everyone that Ajuka is calling out to them at the VIP room who offered to help train them at the training ground and tell Ouryuu to bring them to Belzebut. During training in the Belzebut, Rossweisse was surprise by Ravel’s words that Issei is training hard for her sake and watches as the girls talk about Issei. Akeno asked Rosswiesse about her current feelings towards Issei after the interview and started to think about her feelings.
After returning from training at the Belzebut, Rossweisse wore a revealing lingerie and greeted Issei who also return from his training. She tells Issei that Rias and Akeno won’t be coming to the residence due to the things they had do in the Underworld and Asia will be sleeping with Xenovia and Irina. Rossweisse believes to reject the engagement she must offer herself to Issei and as she held his hand she revealed that she doesn’t want to marry Vidar and wants to be on Issei’s side. She ask Issei to snatch her away from Vidar and Issei responds to her that he never had any intention of handing her over to Vidar, recalling the incident he had with Euclid. Issei hugs Rossweisse asking to believe in her and Rossweisse gives him her first, much to Issei’s shocked. As they were kiss a second time, Kuroka burst into Issei’s room in order to do perverted things with him after learning that Rias wasn’t coming to the residence with Koneko soon following after her sister. Rossweisse gets surprise when Kuroka asked her if she wants to have Issei’s child and gets asked again by her but responded she will be sleeping with Issei which led the four of them sleeping together.
On the day of the match, Rossweisse and her team traveled to Valhalla in Norse mythology at the Thor Stadium. She gets many cheers from the spectators due to Valhalla being her home which causes her to blush from the cheers from everyone. As Team Leisure of the Kings arrives and the match starts Rossweisse goes together with Issei, Irina, Xenovia, Ravel, and Ouryuu to stairways of the artificial Yggdrasil. After Xenovia, Irina, and Ouryuu decided to take on the Chief-God of Olympus Apollon, Rossweisse place a barrier on them in order to keep them from out and she strengthens it with her Misteltein and placed another barrier on the cave where Grayfia and Asia takes on the Goddess Artemis. As they continued, Rossweisse and the others sees Typhon waiting for them at the one the floating islands and later sees Vidar inviting Issei to face him with Rossweisse and Ravel joining and leaving Typhon to Roygun, Bova, and Elmenhilde. While Issei fights Vidar on one on one, Rosswiesse takes on Brynhildr and her former colleagues alongside Ravel. Brynhildr asked Rossweisse if she been training as agrees she brought out her Misteltein as their fight starts. As Brynhildr and the Valkyrie Squad overwhelms Rossweisse with their combined attacks, Rossweisse reveals to them that she kissed Issei, much to their shocked and distraught. When the Valkyrie Squad released their attacking stance, Rossweisse and Ravel released their counterattack with magic and defeated the four Valkyries. In her final battle against Brynhildr, Rossweisse managed to defeat her by barrier magic just on Brynhildr's right foot and uses her Mistilteinn to enhance her offensive magic to defeat her senior. During the battle, Issei confessed to Rossweisse by asking her to give birth to his child and many children, which Rossweisse loudly agrees to give birth many of his children. Rossweisse and her wins the match due to Ddraig defeating Typhon and followed Issei to the top of the artificial Yggdrasil and held hands with him, shyly asking him to see real Yggdrasil to together with her and Issei agrees.
Rossweisse celebrates her victory at the Hyoudou Residence along with her team and the rivals teams. As the girls fight over Issei, she hugs him from his back and says that he is her husband and won’t hand him over in a drunken state after drinking alcohol again.
Powers & Abilities
Demonic Power: As a Devil, Rossweisse has the power common to a Devil. Power to cast spells and special phenomenon, she can also use her demonic powers to enhance her magic skills.
Master Magician: Rossweisse is highly proficient in the use of Norse magic, specializing in long-range and bombarding attacks. She is even capable of using summoning and teleportation spells. According to Le Fay, the Norse magic circles Rossweisse use is of a very rare type, incorporating very high-level magic symbols in her magic formula. Le Fay described Rossweisse's self-invented magic technique as extremely intricate and well made and is of such difficulty that only skilled magic experts can use it. Given the fact that Rossweisse can use such difficult magic techniques so easily is a testament to her great magic skill. In Volume 11, it is stated by Azazel that her power is equal to that of a High Class devil. Rossweisse magic talent is so formidable that she could theorize the creation of a sealing spell powerful enough to seal Trihexa, and even Euclid stated that Rossweisse magic abilities are exceptional and is in no way inferior to her grandmother Göndul a famous master of magic. In Volume 22, Rossweisse can use enhancement magic to enhanced her and others physical abilities. In Volume 25, Rossweisse was able to fight on par with Brynhildr, who is the Strongest Valkyrie in Asgard. In True Volume 1, Rossweisse can use hypnotism magic on Ingvild Leviathan to lose consciousness.
- Elemental Magic: She notably excels in the use of ice, fire, water, lightning, wind, thunder, light and explosive-based magic.
- Defense Magic: Upon returning from her training in Valhalla in Volume 12, Rossweisse starts to use defensive spells (using the trait of Rook), which are strong enough to easily shield against Balance Breakers. She also learned defense magic to negate the adverse effect of touching holy objects such as holy swords and bibles for a short period of time. As seen when she used two of Xenovia's Excalibur fragments (Transparency and Mimic) by putting multiple layers of defense magic on her hand during Rias-Sairaorg Rating Game match and reading a bible without suffering a severe headache.
- Sealing/Barrier Magic: Rossweisse can use sealing magic which she learned by researching information about Trihexa. She could use her Barrier magic to seal the movements of mass-produced Evil Dragons in Volume 19 by studying Asia's Evil Dragons.By modifying her technique, her sealing barrier technique was used by Three Powers to seal the Emperor Beast of Apocalypse. She could also use it in combat to seal her foes. Her barrier was even effective against Armaros, the Grigori anti-magic specialist although she needed time to prepare a stronger barrier as his anti-magic abilities could destroy a half-baked barrier. In Volume 25, Rossweisse, by enhancing her power with Mistilteinn, could use her Barrier magic to seal off entire areas to prevent her foes from escaping.
- Cloth Manipulation: Rossweisse is capable of using magic to altering her attire, changing from her formal suit into her Valkyrie armor.
Flight: Before she was reincarnated, Rossweisse could fly via magic like Loki could. After being reincarnated as a Devil, Rossweisse can now fly using her devil wings.
Mistilteinn Wand: An old-looking wand made out of mistilteinn (mistletoe), possessing powerful magic. In Volume 25, Mistilteinn can strengthen Rossweisse's magic and spells, such as her defensive magic to guard against Brynhildr's magically-imbued sword and strengthen her offensive magic bombardment enough to retire Brynhildr with a single blast.
- Rossweisse's birthday is on August 8th.
- Rossweisse is the name of one of the Valkyries featured in Richard Wagner's opera Der Ring des Nibelungen (The Ring of the Nibelung).
- Rossweisse from German, (Roßweiße) means "white steed".
- Despite being in her late teens, she has already finished high school and most of college in Valhalla.
- In the future, Rossweisse has stated that she wants to establish a Norse magic school in the Gremory territory, and start a business training new Valkyries out of female Devils.
- Rossweisse, being a Valkyrie, is said to be a "Half-God".
- Rossweisse's dream is to build a discount store in her homeland which has every good imaginable.
- Rossweisse is an only child.
- She held the record for the longest duration of being Odin's escort.
- Issei called her "moving cannon" due to the fact that she is a wizard-type Rook.
- Rossweisse reviews and presents 100 yen merchandise on DeviTube. Her videos are a huge hit with the underworld citizens.
- Rossweisse is the third female character to be placed into an engagement, the first being Rias, and second being Kiyome Abe. Among these girls, she is the only one who didn't fall in love with Issei after he saved her as she already loved him before the engagement.
- Rossweisse has a driving license.
- One of Rossweisse's romantic dreams was to go on a driving date with a guy, which she finally fulfilled with Issei.
- In the dub, Rosswiesse is pronounced "Rossvisa" by Issei, Asia, and Azazel.