I plan to create an MC with a personality similar to Nagumo Hajime from Arifureta, only partially because the MC will sometimes be funny. There will be Harem but not any girl that the MC meets. MC will not know the story of DxD. I am basically the same, I have only watched anime and haven't read novels.
If I were to support everyone, I would let the MC go through other worlds like One Piece or Naruto