ArchAngel Gabriel is one of the most powerful beings in the Toaru Majutsu no Index series, a divine entity whose presence alone marks them as a major force in the story. Gabriel is literally called the Power of God, and according to Kaori, rules over water as their divine domain while serving as the guardian of the moon, governor of blue, and protector of the rear side. Acqua of the Back—aligned with Gabriel through God's Right Seat—can perform similar feats of water manipulation because of this connection.
Gabriel's appearance is striking and deliberately ambiguous. They have an androgynous look and are officially depicted as both male and female, though they feature distinctly feminine characteristics including breasts, with no obvious genitalia. Their skin is pure white, covered in an intricate pattern of golden lines concentrated mainly on the upper body, forearms, upper legs, and ankles. These lines converge at Gabriel's chest in a kite-shaped cross symbol (similar to the one on Index's Walking Church), and also appear on the peculiar flaps attached to their wings, head, forearms, legs, and waist.
Topping their head is a blue halo with an inner circle from which three arrow-shaped lines jut outward in different directions. Like the rest of their body, Gabriel's eyes are entirely white with no visible iris or pupil, giving them an otherworldly appearance. While not usually depicted with wings, Gabriel can manifest a pair made of crystallized water whenever needed.
Content compiled by AnimeList.moe from publicly available sources.