[yuiichi9]

I wonder how would be his life married with all of them.

Spoiler for Question:

How issei gets stronger when he push rias's nipples and what with the Oppai-Dragon? When he discover this ability or power. Don't tell that the color page of rias in vol. 9 where she is wearing underwear and there something glowing underneath her have to do something with that ability or power. What do you mean when you said he is a dragon?