Rias Gremory

Rias Gremory is the main female protagonist of High School DxD. She is a Devil from the Gremory Clan - a family of pure-blooded Devils, and is known as the Crimson-Haired Ruin Princess. She is a third-year student at Kuoh Academy, the President of the Occult Research Club, and the school's number-one beauty as well as one of Kuoh Academy's Two Great Ladies.

Appearance
Rias is a young woman who appears to be in her late teens with a buxom figure, a light skin tone, and blue-green eyes. Her most distinctive feature is her long, crimson red hair that reaches down to her thighs, with a single hair strand (known in Japan as ahoge (アホ毛), or idiot hair) sticking out from the top. Her hair also has loose bangs covering her forehead and side bangs framing her face.

Although Rias has worn various types of clothing throughout the series, her most commonly worn outfit is the Kuoh Academy girls' school uniform, which consists of a white long-sleeved, button-down shirt (short sleeves for spring/summer) with a black ribbon on her shirt collar worn under a black shoulder cape and a matching button-down corset, a magenta skirt with white accents, and brown dress shoes over white crew-length socks. Rias also tends to wear seductive lingerie and thongs, especially when she has a desire to sleep with Issei.

On some rare occasions, Rias wears glasses when she's deep in thought, as she feels they make her mind work better despite having normal eyesight.

Personality
Throughout the series, Rias is shown to be kind and soft to her servants. She thinks of Issei as a special person, and always gets jealous when girls are around him, becoming a totally different person when she sees him and other girls together, or when it comes to training.

She is proud of her family's name, but she does not like being seen as Rias of the Gremory Family. The reason for her living in the human world (as revealed in Volume 2 of the novels) is because there, everyone sees her as Rias, not as a Devil or as the Crimson-Haired Ruin Princess.

She enjoys teasing Issei and Asia (from Volume 3 of the novels onward), but at the same time makes it clear (to Asia or any girl) that Issei is hers, and she does not want to share him (It is revealed in Volume 3 of the novels that the Gremory Family and their servants are beings with extraordinary affection among the Devils, so Rias is no exception). She has no problem with showing Issei her breasts or sleeping naked with him (which she always does according to her).

History
Rias is the daughter and second child of the Gremory Family. She became the heir after her brother, Sirzechs, became the Satan Lucifer, losing his right as heir to the house. After being announced as the heiress of the Gremory Clan, Rias was eventually placed into an engagement with Riser Phenex. Prior to the series, Rias has reincarnated Akeno Himejima, Yuuto Kiba, Koneko Toujou, and Gasper Vladi as members of her peerage. She entered Kuoh Academy two years before the series along with Akeno, Sona, and Tsubaki, reviving the abolished Occult Research Club which is used as a base for her servants and became its president.

The Red Dragon Emperor's Awakening
She revives Issei as her servant after the latter was killed by the Fallen Angel Raynare (then as Yuuma Amano). She later saves Issei while he was being attacked by another Fallen Angel, Dohnaseek. Badly injured and in need of medical assistance, she brings him back to his house and spends the night healing his injuries. She later saves him a second time from Freed Sellzen along with the other members of the Occult Research Club. When Issei goes to the abandoned church to rescue Asia Argento, Rias helps Issei indirectly by killing three of Raynare's Fallen Angel allies before terminating Raynare herself. She then revives Asia as her Bishop to Issei's delight.

At the beginning of Volume 2 after the usual daily training with Issei, Rias informs a shocked Issei that Asia will be staying with him, successfully persuading Issei's Parents that Asia's stay is for bride training, making them happy. Rias later goes to Issei's room during night time, attempting to have Issei take her virginity in hopes of breaking her engagement. The attempt, however, was stopped with the appearance of Grayfia Lucifuge, Sirzechs' Queen, who scolds Rias for attempting to break off the engagement set by her brother and father. When Rias' fiancé, Riser Phenex, appears in the Occult Research Club, Rias, who was still unsatisfied with the engagement, agreed to have a Rating Game with Riser under the condition that should Rias win, the engagement will become invalid, and should Riser win, Rias would be forced to marry Riser immediately.

In preparation for her Rating Game with Riser, Rias sets up a training camp in the mountains for Issei and Asia who both lack fighting experience. During their training in the mountains, Rias starts to develop strong feelings for Issei due to Issei's feelings for her. On the day of the Rating Game, Rias faces Riser in a replica version of Kuoh Academy set up in a dimensional space. While the battle initially went well for Rias' team, they ultimately lost due to the lack of people on her team, surrendering after seeing Issei being beaten to near-death, yet still standing, trying to fight for her. She was later seen at her engagement party in the Underworld, which was interrupted by Issei who came to challenge Riser one more time with Rias' engagement on the line, with Issei succesfully winning this time. After Issei helps to break off the engagement between herself and Riser, Rias falls in love with Issei and kisses him for the first time. She moves into Issei's house after the incident with Riser.

Birth of the Breast Dragon Emperor
In Volume 3, Rias introduces her new servants, Issei and Asia, to the Student Council members led by Sona Sitri, a pure-blooded High-Class Devil from the Sitri Clan who is her childhood friend and rival. After Issei noticed Yuuto's change after seeing his childhood photos among one which Issei took with his childhood friend, Irina Shidou and her father who was holding a Holy Sword, she explains Yuuto's past to Issei and was greatly disappointed when Yuuto left her to seek his revenge after seeing both Xenovia and Irina. She and Sona eventually found out the alliance Issei, Koneko and Saji made with the church duo to destroy the Excaliburs, punishing the two of them for their actions. When Kokabiel, one of the leaders of the Fallen Angels, announced his war declaration against both the Gremory and Sitri clans who are attending the Kuoh Academy, Rias gathers all her servants (except for Yuuto who is still missing) in an attempt to fight back while having the Sitri Group as support. During the fight, Kokabiel summoned out many Cerberus to battle the Gremory Team but was defeated by the combined effort of the Gremory Team and Xenovia who arrived at the battlefield. After Yuuto attained his Balance Breaker and broke the Excalibur with Xenovia's help, the Gremory Team was then forced to battle Kokabiel himself but were easily overwhelmed by the Fallen Angel Leader and was in despair until the sudden interference of Vali Lucifer who came to retrieve Kokabiel under Azazel's order.

In Volume 4, after Issei reports on his meeting with Azazel much to Rias' anger on Azazel's action, they are surprised at the sudden appearance of Rias' brother, Sirzechs Lucifer, who came for Rias' class observation, telling Rias that Azazel won't do any drastic action like Kokabiel. Rias later unseals her other Bishop, Gasper Vladi, a half-Vampire who she revived as a Devil using a Mutation Piece, after receiving orders from the top-brass. During the peace talk between the Three Factions, Rias is asked to report the events that happened during Kokabiel's attack and assisted when the Khaos Brigade attacked using castling to rescue Gasper who was used by the terrorists. Near the end of Volume 4, Rias is seen troubled when Azazel introduces himself as the advisor for the Occult Research Club, getting angry at Azazel when he suggested to take Issei on a virgin graduation tour, telling Azazel that Issei's virginity is under her watch. She also decide to renovate Issei's house after Akeno and Xenovia moves into the Hyoudou Residence.

In Volume 5, Rias returns to the Underworld for the Young Devils Gathering in which they will fight in Rating Games. Before the opening ceremony for the Young Devils Gathering, Rias introduces her cousin, Sairaorg Bael, to Issei, telling him that Sairaorg is the strongest young Devil. On the opening ceremony of the Young Devils Gathering, all the six chosen young Devils are asked to step up and speak out their dreams. The ceremony ended with Sirzechs announcing the first match for the Young Devils Gathering that is between Rias and Sona. During the party set up by the Sirzechs Lucifer for the young Devils, Issei and Rias notices Koneko rushing out of the party hall and follow pursuit, seeing Koneko's older sister, Kuroka, who attempted to bring Koneko back with her, with Rias objecting, claiming that Koneko is her Rook and she won't allow anyone, even Kuroka, her biological sister, to take her away. Feeling troublesome, Kuroka then uses a special mist that effects both Rias and Koneko, limiting their mobility. Despite so, Rias was still useful in the fight, as her breasts were used by Issei to attain his Balance Breaker. She later faces her childhood friend and rival, Sona, for her first match in the Young Devils Gathering and won due to Issei and Yuuto's aid but was unhappy with the victory because she had to rely on Yuuto interfering her fight with Sona and losing four of her servants. Near the end of Volume 5 while on their way back to the human world, the team was surprised to see Diodora Astaroth who introduces himself.

In Volume 6, she was scheduled to face Diodora for her second match in the Young Devils Gathering rejecting Diodora's offer to exchange servants. During the day of the Rating Game, Rias and Diodora's supposed Rating Game did not occur due to the Khaos Brigade's interference and the revelation of Diodora's alliance with them. After Diodora kidnaps Asia, Rias and her peerage go to rescue her. During Asia's supposed "death", Issei's negative feelings made him activate his Juggernaut Drive and go berserk, until Irina came with a recording of the new song written by Azazel and her brother, allowing Issei to regain part of his sanity before having Rias use her breasts to cancel the Juggernaut Drive.

The Heroic Oppai Dragon
At the beginning of Volume 10 of the light novels, Rias' mother, Venelana, encourages her to push her relationship further with Issei, in which Rias would attempt to seduce Issei but she got upset when Issei could not call her by her name and she left in tears. She also faces her cousin, Sairaorg Bael, in a Rating Game which Rias' team won after Issei beats Sairaorg, making Rias the winner of the Young Devils Tournament. At the end of the same volume, Issei finally confesses and calls her Rias for the first time instead of President. She sheds tears of joy and tells him that she feels the same way and the two officially become a couple.

In Volume 11, She accompanied Issei, Akeno and Yuuto during their Middle-Class promotion test with Issei asking her out on a date should he pass the test. While Issei and the other two are resting the after the test, they are ambushed by Cao Cao and Georg who came to steal Ophis' powers. The battle ended with the Gremory and Vali Teams losing to Cao Cao and Ophis' powers stolen. Both teams were then attacked by a legion of Grim Reapers and Siegfried. They eventually overcame the situation by having Issei use Rias' breasts to replenish Issei's magic and successfully force their enemy to retreat. At the end of Volume 11 while waiting for Issei to return from the crumbling dimension, Rias like the rest of the Occult Research Club was surprised that only Issei's Evil Pieces returned, and was shocked to find out that Issei died.

In Volume 12, Rias, who was still at shock at Issei's "death", locked herself in her room and was not responding to anyone until Sairaorg came and talked some sense into her. She and her peerage later goes to the human world to meet with the creator of the Evil Pieces, Ajuka Beelzebub, to have him check on Issei's Evil Pieces and are surprised to see the Khaos Brigade's Old Satan Faction and Hero Faction coming to see Ajuka, intending to form an alliance with the latter which was rejected as Ajuka finishes off the Old Satan Faction members, leaving Siegfried to the Gremory Team. Like the rest of the girls, however, Rias was unable to display her usual strength until Issei's Evil Pieces glow and conveys his feelings to the team, allowing them to regain their determination to fight. After Ajuka confirms that Issei's soul is still alive she and the rest of the Occult Research Club were extremely happy, looking at the news to confirm the current status of the Underworld until hearing that the Sitri Group is engaging the Khaos Brigade in the town area as they head out to battle the Khaos Brigade. After Issei returns, Rias inserts back Issei's Pawn Evil Pieces into his body kissing him. At the end of Volume 12, Rias congratulates Issei for passing his Middle-Class promotion test, asking him out on a date as promised before the test.

The Legend of Oppai Dragon and his Lively Companions
In Volume 14, Rias and her peerage meet the director of the Magician Council, Mephisto Pheles, regarding their pact with the Magicians. Rias also mastered a new finishing attack during her training with Akeno. After the negotiation with the Carmilla Faction from the Vampire side, Rias was angered by their means of obtaining Gasper by using the peace negotiations of the Three Factions to force them to hand over Gasper or risk allowing the Devils to lose trust on their intentions of achieving peace. She later decides to leave for Romania with Kiba and Azazel in order to learn more about Gasper's ability.

Powers & Abilities
From her mother, Rias has inherited the Bael Clan's Power of Destruction. This power allows her to release energies that can disintegrate matter, both living and inanimate, with relative ease. Opponents who wield sufficiently greater power, however, can shield themselves from this. In Volume 14, after her training with Akeno, it is revealed that Rias perfected a special one-hit kill move which is described as a compression of unimaginable amounts of demonic power. It has the appearance of an enormous sphere with a mixture of crimson and black aura radiating from inside of it. Rias claims that she created it by solely concentrating on destruction and strengthening it, after having experienced the constant assaults from the terrorists and the death of her beloved. The extent of its power is unknown but it is stated to be extremely dangerous, with its power surpassing the retiring system in the Rating Game.

Rias has all the common skills and powers of a Devil. She is also shown to be at least somewhat proficient in the use of spells, such as the ritual to drain energy from Issei's left hand to let it appear human again, healing, teleportation by magic circle, and others.

As a sister of Satan, the light novel hinted that her power is high compared to other Devils at her age. In Volume 1, she and Akeno are able to defeat three Fallen Angels with relative ease. In Volume 3, with a 8-time boost from Issei, she is able to force Kokabiel on the defensive. Although it is blocked, Kokabiel is not completely unharmed either. In Volume 6,  Azazel shows a graph of abilities for the young Devils that is based on the four categories of Power, Technique, Support, and Wizard, along with an additional category, King. It is shown that Rias excels more in the Wizard and Power categories while averaging in both Technique and Support. Her quality as King is shown to be fairly high.

Rias has gained the ability to project a red light from her breasts, which recharges Issei's energy. Each use of this power causes her breasts to temporarily shrink in size, which makes Issei cry even though it's sometimes necessary. Her breast size will restore itself after a few days of rest.

Quotes

 * (Introducing herself to Issei) "My name is Rias Gremory. I am a Devil. And I am your Master. Nice to meet you, Hyoudou Issei-kun. Can I call you Ise?" (Volume 1, Life 1)
 * "There's one last thing you should never forget, Ise. Even a [Pawn] can take down the [King]. This is basic in chess. This truth also applies for the Devils' chess pieces. You can become stronger." (Volume 1, Life 4)
 * (To Issei) "Geez... You're an honest kid with perverted thoughts too. Ufufu~♥" (Manga, Chapter 22)
 * "Now my adorable servants! Let's blow away the enemy before us as the Gremory group!" (Volume 12, Life -2)
 * "Insulting my servants warrants death!" (Season 2 New)

Trivia

 * Rias' body measurements are B99-W58-H90 cm. (B39-W23-H35 in.), her height is 172 cm. (5 feet 8 inches), and her weight is 58 kg. (128 lbs.), according to the visual book with her data. Her breast size is the second largest recorded in the series, just behind Akeno Himejima.
 * Rias' birthday is April 9th, according to official material.
 * Rias plays the heroine, the Switch Princess, in Breast Dragon Emperor Oppai Dragon.
 * In one of the short stories, it is revealed that Rias is an anime otaku, having a huge collection of figures and posters in her room back in the Underworld.
 * Rias prefers to sleep naked, as shown on many occasions throughout the series.
 * Rias' breasts have a high-pitched voice as shown when Issei first used his Bilingual ability on Sona Sitri and her peerage during a Rating Game match at the Young Devils Gathering.
 * Rias' name is a references to Lias' Pawn, a Fairy chess piece that can move one step to the side, as opposed to the standard pawns who can only move one square up. This idea was first proposed by A.G. Lias in the 1920s.
 * The name Rias is due to the differences between "R" and "L" in the Japanese language, with the latter letter being almost nonexistent. However in the official anime PV and other promotional material, her name is spelled with an R, thus making it her official name.
 * In the manga and light novel while Rias and Issei were on the Griffin after the fight against Riser, she "jokingly" asks if Issei wanted her virginity after sharing their first kiss, and he excitedly exclaims that he does. This scene was omitted from the anime.
 * Rias is known as one of the "Rookies Four" along with Sairaorg, Sona, and Seekvaira.