Tiamat is one of the Five Great Dragon Kings and one of the few legendary Dragons left who are still active since ancient times. She can also be mischievous as she came up with the idea that since Ddraig was unable to retrieve her lost treasure, Issei needs to take Ddraig's place in retrieving her lost treasure. Despite her anger towards Ddraig, Tiamat was very calm towards her meeting with Ddraig.

She also shifts the blame onto the possessor of the Boosted Gear, Issei Hyoudou, saying they need to take responsibility for her treasure or she will burn them to death. Tiamat hates Ddraig for losing her borrowed treasure, which was stolen and scattered. She also wears a navy blue skirt, and her entire body is doused with the color of deep blue.

She possesses an extremely powerful dragon aura within her body.

In her human form, she has the appearance of a beautiful woman with straight and long beautiful pale blue hair, dark blue eyes, and a cold atmosphere that radiates from her beauty. In her normal dragon form, Tiamat has the appearance of a pale blue Western Dragon with celestial blue scales.

High school dxd dragons