Michael is a character in TJOC Story Mode. He is the main antagonist, a “Phone Guy” of sorts for the other family members and the reason the animatronics escaped from the game. As it is revealed, the Ignited, Fallen and Michael himself are actually demonic dopplegangers as revealed by Nikson.

He helps the others in Scott's family, as they do not need to die for his plot to stay in the real world. He goes after Scott, and only Scott, shackling him to a chair and leaving him to die in the attic, later killing him in the burning house via taking over his body. 

In the Ending, he led Scott on by trapping him in the Attic when he told Val that he was going to "help" him get out of the house.

His dialogue in the attic opener cutscene tells us that this is Michael Schmidt, as in his own words, "Being Michael Schmidt has been an incredible experience." 

it is implied that he is Mike Schmidt from fnaf