Review Detail of LonelyDevourer in HighSchool DxD: Fan-fic

This is the best fanfic of dxd I ever read that does not change to much of the actual plot. The story is just like in the anime. But if I have to add something is that can you make the mc body grow stronger through mana/chakra or any other type of energy by enhancing his body since I can only picture BB by having a strong body