Ophis

Ophis is the Dragon God known as the Ouroboros Dragon and the Infinite Dragon God. She is the founder and former leader of the Khaos Brigade. She was the second most powerful Dragon in existence, after Great Red, before losing a large part of her powers in Volume 11 because of Samael's curse. Her powers were later used for giving birth to Lilith.

Appearance
Ophis' current appearance is that of a young girl with long black hair down untill her hips and gray eyes. Her ears differ from a normal human's as they have pointed tips, although her long black hair makes this feature difficult to notice. Azazel stated that Ophis had the appearence of an old man in the past before changing it.

Her attire consists of a black Gothic Lolita fashion.

However, Ophis is a true shapeshifter being able to freely manipulate her body shape and size so as to assume any form that she chooses, regardless of her age, race, or gender. Unlike the other Dragons that have large reptilian-like bodies, Ophis is a human-shaped Dragon.

Personality
Being born from nothingness, Ophis rarely shows any sort of emotion, only wanting to get rid of the Great Red and return to the Dimensional Gap to obtain "silence". Issei describes Ophis as an honest and pure Dragon who is naive. Azazel indicates Ophis has changed because of her interaction with humanity, but how is never described.

In a side-story, Ophis shows a somehow really rude but accurate way to describe people.

History
Some time in the distant past, Ophis was born in the Dimensional Gap, and lived there as its home. Eventually, long ago, Ophis left the Gap, but when it attempted to return, found that the Great Red had taken up residence there. Before assuming her current form, she used a different guise in the form of an elderly man. At some point before the start of the series, Ophis became the leader of the Khaos Brigade.

Birth of the Breast Dragon Emperor
Ophis' name was mentioned in Volume 4, in which Ddraig calls her "the strongest existence".

She made her official appearance in Volume 6 in the Underworld to look at the Great Red before retreating. She was asked by Sirzechs if she would quit the Khaos Brigade but refused since Sirzechs refused to give her the area of the dimensional rift and to surrender to her rule.

The Heroic Oppai Dragon
She reappears in Volume 11 at the Hyoudou Residence along with Le Fay Pendragon, Fenrir, and Kuroka, wanting to observe Issei as he was having unusual growth of powers. Her powers were later stolen by Cao Cao and Georg who used Samael on her. At the end of Volume 11, she was kidnapped by Shalba Beelzebub with Issei rescuing her but receiving Samael's curse as a result.

In Volume 12, Ophis and Issei were on top of the Great Red after he passed through the crumbling dimension they were both on, rescuing the two of them. She then used her powers on Great Red's flesh to form a new body for Issei. When Issei returned to the Underworld, Ophis guided Issei by sensing where his friends were, telling him the directions on how to get there. Following the crisis in the Underworld, she moves into the Hyoudou Residence at the end of Volume 12 to continue "observing" Issei much to the shock of the other girls, as a part of her was used to recreate Issei's body with Great Red's flesh.

In Volume 13 Extra Life, Ophis is seen playing with Rassei whom she has developed a close relationship with, even going as far as stating that she will train the young Dragon.

The Legend of Oppai Dragon and his Lively Companions
In Volume 15, Ophis is seen atop Fafnir's head and has Rassei on top of hers and said that with their combination, she thinks they could challenge Great Red.

In Volume 16, Ophis remained in Japan when Issei and his friends left to Romania but not before Ophis gives Issei some warning about the Evil Dragons.

Powers & Abilities
Snakes: Ophis has the ability to manifest her powers in the form of snakes. These snakes have the ability to increase a person's power tremendously by consuming it. Another type of snake she creates can be used to bring out a Sacred Gear's full potential. While this can potentially lead them to achieving Balance Breaker more quickly, it can also break the Sacred Gear, killing the host.

Shapeshifting: Ophis is a true shapeshifter, able to alter her size, apparent age, physical attributes and characteristics, and even her apparent gender.

Immense Strength: According to Ddraig, her true abilities are stronger than the two Heavenly Dragons combined. So much so that when her powers were reduced to a level twice as powerful as the Heavenly Dragons, she felt "weak."

Blessing: Ophis can 'bless' people, granting them certain advantages. These blessings don't seem to have a negative affect on Devils. With Asia, the blessing has increased her compatibility with Dragons, while with Irina, it has increased her luck.

Quotes

 * "He wasn't a bad person. He was my first friend." (Volume 11, Life...)
 * "I, like doughnuts, cookies." (Volume 12.5, My Fist Errand [Ophis Volume])
 * "I, went under for 30 minutes." (Volume 14, Life 2)
 * "I, appear from the closet. Ehem." (Volume 14, Life 3)
 * "I, shall swim." (Short-Story, Let’s Go to Onsen!)

Trivia

 * Ophis represents Infinity, Chaos and Nothingness.
 * Ophis was born from the "nothingness" of Infinity.
 * Ophis was ranked #1 among the the Top 10 "Strongest Beings in the World" before losing her powers.
 * Ophis was originally set to die after resurrecting Issei
 * Ophis' name means "snake" in Greek, referring to her powers revolving around snakes.
 * The nickname "Ouroboros Dragon" refers to Uroboros, the Infinite Snake of the Norse mythology.
 * Ophis is genderless, as revealed in her side story.
 * In the Afterword of Volume 12, the author indicated that Ophis was originally not meant to join Issei's Harem, but after seeing her on the cover, they decided to make her a mascot character.
 * Before the introduction of Great Red, Ophis was stated to be the most powerful being in existence.
 * It is theorized by Sona Sitri that the reason that Ophis sticks so close to Issei is because she is possessing him, to the point that he "shoulders a karma that no God can purify".