Mikhail

A god that possesses Teito's body through the Eye of Mikhail. When in control of Teito's body, Teito's irises become red and his pupils become slits. He is very fond of Teito, and is put out by the slave collar that limits his strength. Though extremely powerful, he tends to act like a petulant child and often makes undignified faces when talking with the Bishops.

~Wiki