The Spirit of Light is a pure spirit, unlike the depressing and fallen descendant of darkness spirit. He is capable of bestowing divine protection onto heroes. Ramiris and he are supposed to do that together, but that rarely happens.
He is a human-shaped spirit, a boy.
The last time he and Ramiris blessed a hero together was, two thousand years ago.
After Ramiris got really bored and decided to become an evil spirit, bestowing divine protection became his job.
After listening to the children's story, and seeing that Kenya had a good disposition towards the light, he decided to help Kenya. So, until Kenya grows up, the Spirit of Light will protect him. He has even stated that it possible for him to become a hero. Saying so, and without waiting for permission, he entered Kenya. Quickly stabilizing his body.