Penultimate chapter will be our MC almost turned into a godlike warrior eradicating all the villains while all the girls are riding him.
And the final chapter will be him dying from snu snu.
@Rover I think it's stated its possible to have the same peach abilities before and yuukis sister shows its possible to eat multiple peaches. So maybe so can the giant girl and you can tell her slave mode is him going giant. Maybe even his sister will develop the ability. I get the feeling his ultimate mode will be raiju the lightning wolf.
@Renard I'm calling the giant girl will get a new ability and yuki gains a giant mode and his ultimate mode mode might be a raiju a lightning wolf but I get a feeling he will gain a mode with a sword maybe become a samurai.