Transmigrating to a Female-oriented Novel, My Junior Sister is the Villain

(Multiple female leads, a love triangle, slightly yandere later on, definitely a reincarnation)

Su Yi was originally a loyal fan of open-world games, but he was reborn into a game adapted from a female-oriented novel. The Godly Might Lord, who originally had no children, suddenly had him as his child.

The junior sister she watched grow up would fall into demonic possession? Her sect would be destroyed? The heroine, burdened by misfortune, felt despair for the world.

I don't pay attention to the storyline when I play games! But I can't skip this part of my life, can I?

Save my junior sister, save the sect, save the female protagonist—no, I mean save the female lead, let her save the world!

However, things don't seem to be going very smoothly.

Junior sister: I was here first, so why is senior brother paying so much attention to her?

Female lead: He clearly says that leaving me would be dangerous, so why does he always go to see his junior sister?

In unison: Who exactly are you concerned about?!