Villainess Level 99: I May Be the Hidden Boss but I’m Not the Demon Lord

I reincarnated as the "Villainess Eumiella" from an RPG Otome game. In the main story, Eumiella is merely a side character, but after the ending, she re-enters the story as the Hidden Boss, a character boasting high stats on par with the heroes! Lighting a fire in my gamer's soul…