Wandering legend, everyone will just think that he's just a myth everyone integrated into their lore, but cant find his origin. With this he could become a god mysteries?
So dude is gonna be on a quest to become a god of every pantheon like Egyptian gods, etc. Maybe you should put some side quests, otherwise it's just gonna be him meeting new gods and becoming more powerful.
God of knowledge? Knowledge is still considered different from wisdom. Dude can teach others to be wizards to strengthen his divinity of magic so it can be useful.