I think they should just bring him back, In my honest opinion he was the best MC. The game is just non-sense with all this religious stuff, leave the succubus to the anime people.
From my perspective, what made Lust Epidemic an interesting game was the story, not just the random sex with imaginary pixel characters.
in ToN was definetly the music, the visuals and the girls.
In this game, I dont know what they were thinking. I imagine they just threw both games into a bowl and made a salad out of it, that is why this game made no sense and it was random sex with very little context.
I am pretty sure from the trailer it'll be mechanically a continuation of this game, hence I am very little interested in playing this next game