Asia Argento

Sister Asia Argento is the deuteragonist of High School DxD. A beautiful nun whom Issei met while in town, she is a girl with a very gentle heart who possesses a divine Sacred Gear, Twilight Healing, in her body that is capable of healing the wounds of Humans, Angels, Fallen Angels, and Devils alike.

Appearance
Asia is a girl around 15-16 years of age with long blonde hair and green eyes. Her hair flows all the way down to her back, with split bangs over her forehead and a single strand sticking out from the top, sloping backwards. Her main outfit consists of a dark teal nun outfit with light blue accents, a white veil over her head with light blue accents, a brown sachel slung on her right hip (where she holds her Bible), and brown boots with black straps in an X-shaped pattern. She also wears a silver cross necklace around her neck (she was later forced to remove it after becoming a Devil). Of all the girls of the Occult Research Club in terms of breast size, hers appears to be among the more "modest."

Upon transferring to Kuoh Academy, she wears the Kuoh Academy girls' uniform, albeit with a black sweater-vest over her dress shirt in place of the cape and corset.

Personality
As befitting a nun, Asia is extremely innocent and fairly inexperienced in things like socializing. Despite being reincarnated as a Devil, Asia still believes in God and follows His teachings such as praying to Him and reading the Bible, which would usually result in her getting severe headaches. Asia was also in deep shock when she learned that the God of the Bible is dead from Kokabiel.

History
Asia was abandoned by her mother when she was a baby and was raised in a church. Some time during her childhood, she gained the ability to use her Twilight Healing and became known as the Holy Priestess. It was during that time that Diodora Astaroth made a plan to have Asia heal him, a Devil, and caused her banishment from the Church with people labeling her as a witch. With no place to go, Asia had to rely on the Fallen Angels.

The Red Dragon Emperor's Awakening
Asia first appeared in Volume 1 as Raynare's underling, which in reality was a plan by the latter to steal Asia's Sacred Gear. After having her Sacred Gear removed from her body which resulted in her death, Rias revives her as a Devil under her as her Bishop. She moves into the Hyoudou Residence after Issei rescues her from the Fallen Angels and transfers to Kuoh Academy, where she is in the same class as Issei.

In Volume 2, she moves into Issei's house with Rias' help. She later goes to a mountain to train in preparation of the Rating Game between her master and her then-fiance, Riser Phenex. During the Rating Game, she stayed back at the headquarters with Rias due to her lack of combat abilities. She accompanies Rias when she goes to the enemy's headquarters, healing Rias while she is fighting Riser but gets knocked out by Riser's Queen's attack with Issei shielding her. After Rias resigns from the match following Issei's defeat at Riser's hands, Asia spent 2 days trying to heal Issei but to no avail and was happy when he woke up. When Issei heads to the Underworld to rescue Rias, Asia wanted to follow but was stopped by Issei. Asia, however, makes Issei promise her that he will win and bring Rias back with him.

Birth of the Breast Dragon Emperor
In Volume 3, during Xenovia and Irina Shidou's visit to the Occult Research Club to tell the Gremory Team to not interfere in their job, the two eventually met Asia remembering as a former "Holy Maiden", calling her a "witch" for sinking so low to becoming a Devil. She was also shocked to learn that the God from the Bible died from the Great War from Kokabiel.

In Volume 4 during the conference between the three factions, Issei wanting to know why Asia was exiled from the church despite her beliefs from the Archangel Michael, which Michael responds that after the death of the God of the Bible, the system of the Heavens become inoperable until he and the other Seraphs took over but was unable to operate it like the God from the Bible. Due to this, the belief in the religion weaken and they had no choice but to kick out those that might seem like a threat to the system. When asked by Michael on her current lifestyle, Asia happily responds that she is fond of her current lifestyle and has gain lots of friends and family.

In Volume 5, Asia goes to the Underworld along with the other members of the Occult Research Club for the upcoming Young Devils Gathering that Rias has to attend. During the Rating Game between Rias and Sona Sitri, Asia was eliminated when trying to heal Issei from his blood loss but her healing aura turned into an offensive aura by Momo Hanakai's reversing skill that ended up eliminating Issei and herself. At the end of Volume 5, she remeets the Devil she saved in the past, Diodora Astaroth, who proposes to her.

In Volume 6, she was kidnaped by Diodora during the Rating Game between Rias and Diodora, who was at cohorts with the Khaos Brigade's Old Satan Faction. It is then revealed that Diodora was the one who set up Asia's excommunication from the Church. Asia was then sent into the Dimensional Gap by Shalba Beelzebub, which triggered Issei's Juggernaut Drive but was rescued by the Vali Team.

The Heroic Oppai Dragon
In Volume 9, Asia and the other second-year students of the Occult Research Club took part in the class trip to Kyoto. Prior to the trip, she was given a special card to allow Issei to use Promotion without the King's presence.

In Volume 11, Asia accompanies Issei, Yuuto and Akeno to the Underworld for their middle-class promotion test. While resting, Asia asked Azazel on whether or not she can attained Balance Breaker, which Azazel confirms, saying that she might even obtain a sub-species Balance Breaker but asked her if she knows her weakness, which Asia asks if it is the fact the she is useless in battle aside from healing. Azazel, however, advices Asia to make contract with other creatures aside that have strong defense after confirming that Asia has a Sprite Dragon under her. When Cao Cao and Georg attacked the Gremory and Vali Team, Cao Cao used one of the ability of his Balance Breaker to redirect Kuroka and Le Fay's attack towards Asia and an injured Xenovia, forcing Issei to use his Trident Knight to protect them, making him incapable of battle. At the end of Volume 11, Asia, like the rest of the girls of the Gremory Team, was surprise to see only Issei's Evil Pieces return and was confused, asking where is he.

In Volume 12, Asia and the Gremory Team stayed in the Gremory Palace, as the whole team was still at shock at Issei's "death" with Asia proclaiming that she wants to go to Issei's place but knows that Issei will be angry at her for doing so. Later, the Gremory Team went to visit Ajuka Beelzebub in the human world, where they are confronted by Siegfried and the Old Satan Faction. When Yuuto and Siegfried fight one more time, Asia's healing did not show much effect due to her lack of will to move until Issei's Evil Pieces glow and transferred his thoughts to Asia, allowing her to regain her will.

Powers & Abilities
Asia has the Sacred Gear Twilight Healing, which allows her to heal Humans, Devils, Angels, and Fallen Angels alike. Asia herself shows no actual fighting technique, and mostly relies on her healing abilities. She can send the healing powers of Twilight Healing in a form of a projectile, but it is slighty inferior to her direct touch.

In Volume 12, it is stated that Asia can create a bow and arrow of healing power, and if the arrow is about to hit an enemy, it will disperse instead of healing them.

As a Bishop, Asia has a greater amount of magical power at her disposal, though at present only uses it to power Twilight Healing.

Trivia

 * Asia's body measurements are B78-W55-H81 cm. (B31-W22-H32 in.) and her height is 155 cm. (5 feet 2 inches), as revealed in the visual book with her data.
 * Asia is the only girl whom Rias allows to sleep with Issei (aside from herself).
 * Azazel has stated that Asia has mastered her Sacred Gear to the highest level to a point that even if she achieved Balance Breaker, it will merely scale up her mastered skills.
 * Asia's last name, Argento, suggests that she is of Italian descent. Also, she shares the same name and surname of an Italian actress.
 * Asia's last name is also the Italian word for "Silver", in reference to the silver cross she once wore prior to being revived into a Devil. Silver crosses are common among the Catholic clergy, particulary exorcists.
 * Asia's breasts are revealed to be tsundere when Issei first used his Bilingual ability on Sona Sitri and her peerage during her and Rias' Rating Game at the Young Devils Gathering.
 * Asia has stated a desire to join Issei's Peerage when he becomes a High-Class Devil.