Despite what you may be thinking, this isn't Amaterasu - it's a character I played in a superhero game called Mutants and Masterminds based off of Ammy.

I just called him Okami (which means Great God, or Great Spirit), and his backstory is that he was a powerful god in a time before time, but he used up all of his power to seal away an evil god of equal power. He fell into a great sleep, only to awaken in the modern day, weak, and aware of the evil god's growing power.

His whole thing is that his powers are based on faith, so he needs to rebuild his reputation with the people of this modern day by being a hero to gain enough power to put a stop to this coming god.

He's probably golden with red markings or something.