Another Gremory!?

What if Rias had a brother who was different from his family. He ran away on his own birthday never to be seen again but years later he's the most power fighter because of his hollow, demonic, chakra, and goddess of dragons. Reason why he ran away? Well wait for the story.

I never any of the anime at all but if I did own Naruto I would fix Boruto so it can be like Naruto again