My Harem Consists Entirely of Female Demon Villains

I, the earthling "hero" of this story, crossed over into another world based on a video game and suddenly appeared in a villainous female demon's bed when I arrived. If not for the fact that I had married all the villains in the game before crossing over, I'd have been killed pretty quickly. Now, the villains keep pestering me, asking me to help them rule the world, and vying for my hand in marriage. What am I supposed to do? I'll await your answers online! It's urgent! (Source: Bilibili Comics)