The Last Ender Dragon: Reincarnation
"Why am I here?"
"There is a hero summoned from a dimension without magic at all. They are beings of pure light and goodness meant to rid this world of the evil trying to overtake it. You aren't him. Your life from here on is to make sure that in case he loses that you are strong enough to stop the demon."
Rowan Kairos was anything but average and ordinary on earth before he was killed by demons, now in a new world he is forced to learn magic in order to fulfil the wishes of a mysterious god.
He isn't human, a dragon like no other with no direction. His only guild is the dungeon creators tomes and the many companions he will make on the way.
But the evil in this world is great, and a hero is there to stop it. He's just insurance in case that guy fails...