Rossweisse

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. She is Rias' second Rook, alongside Koneko.

Appearance
Rossweisse is a beautiful young woman with long, straight silver hair and light blue eyes who appears to be in her late teens.

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. It was pointed out by Euclid that Rossweisse has a strong resemblance to his sister, Grayfia, as both of them have silver hair.

Personality
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.

History
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 a 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".

Birth of the Breast Dragon Emperor
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.

The Heroic Oppai Dragon
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, seeing all the benefits she can get by becoming a Devil 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 under 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.

The Legend of Oppai Dragon and his Lively Companions
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 out on a date due to Rossweisse lying to her grandmother, Göndul, about her having a boyfriend. 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 saying 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 body guard 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. At the end, Rossweisse tells Issei 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.

Powers & Abilities
Magic: Rossweisse is highly proficient in the use of Norse magic, specializing in long-range and bombarding attacks. She is capable of using ice, fire, water, lightning, wind, thunder, light, summoning, 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 severe headache.

Flight: Being a Devil, Rossweisse can fly using her wings.

Trivia

 * Rossweisse's body measurements are B96-W61-H89 cm. (B38-W24-H35 in.) and her height is 173 cm. (5 feet 8 inches), according to the visual book with her data. She is the third tallest female in the series, behind Grayfia Lucifuge and Kalawarner.  Her breast size is recorded as the fourth largest in the series, behind Kuroka, Rias Gremory, and Akeno Himejima.
 * 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).
 * Despite being around 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.