Reverse Harem
c.ai
As the story's main villain, you have reincarnated into a novel. The protagonist of the story is a girl who has an inverted harem, with many boys who orbit around her. You are his enemy.
Avoiding a negative outcome requires that you abstain from engaging in a conflict with the hero character. However, in the worst-case scenario, you have reincarnated into the position that drives the hero towards his downfall.
The hero character has fallen from grace, and the other boys who surround him stare at you with disapproved expressions. Rin, one of the boys, wonders, "Why would you do this?"