A legendary red stone that is said to have fallen from the heavens, and which allows the archangel Mikhail to possess Teito's body through it.
When the Eye of Mikhail is in control of Teito's body, Teito's irises become red and his pupils become slits. The Eye itself is visible in Teito's right hand.
Mikhail is arrogant, childish and hot-tempered, but is very kind and respectful towards Teito, whom he sees as his true master. Mikhail is apparently also very aggressive, readily attacking anyone who has offended him, or who has tried to hurt his master. He is very protective too. He always protect his master (Teito) when he was about to break.
Mikhail has the ability to wield strange, branch-like protrusions from the area around the Eye in Teito's right hand, which can be used to attack opponents. He also can create nightmarish illusions to frighten others, as seen in episode 10 of the anime, where he frightened Frau and Castor with an illusion of a hellish-looking place after they annoyed him by doubting his authenticity as a god. He has also displayed the ability to create several massive explosions over a wide area in episode 20 of the anime, blowing up many military machines in the process, and put people into comas, as demonstrated with Haruse. In addition, he has been shown to be able to restore some of Teito's memories, and it is likely that he is able to send people to hell, as he said to Assistant Archbishop Bastien, who was tainted with darkness,'Please allow me to guide you to the pits of hell.', in episode 18 of the anime.
With Teito: Mikhail has a great deal of respect for Teito, and always sounds gentle when speaking to him. He is fiercely loyal to and very fond of Teito, and has also professed admiration for Teito's beauty.
With Zehel: Mikhail is very annoyed by Zehel's teasing attitude towards Teito, as shown when he aggressively attacked the previous reincarnation of Zehel, Gido, when Gido made fun of Teito (as seen in a chapter of the manga). He also apparently does not like the fact that the current reincarnation of Zehel, Frau, teases Teito for his short stature. He also seems to enjoy taunting Zehel in return, saying to him 'We would have been fine even if you hadn't shown up.' when Zehel comes to rescue Teito in episode 18 of the anime, and ordering Frau around in a track on one of the drama CDs. However, the two may not necessarily dislike each other, and may have some level of understanding of each other, as Zehel has said to Mikhail, 'I wouldn't mind dying by your hands.' and in chapter 44 of the manga, Mikhail has said to Zehel, 'Protect him (Teito) with all your powers in my place.', showing that he trusts Zehel to protect Teito when Mikhail himself is unable to do so. Zehel has also stated that he is watching over Mikhail because he knows the true significance and purpose of the Eye's existence, in episode 18 of the anime.