IsekaiFan
author, I hope you don't make him get involved in all the demons' problems like a nosy as if it were his responsibility, in several fanfic they do that and it's very annoying, that they get into where they are not called just for being in the plot. DXD demons are very annoying thinking big, looking down on humans, when they depend on them for survival. And for me the group where it would fit would be with Vali's, since it can have more adventures than with the boring plot of rias and the later ones.