This manga, and the revenges don't show anything unique or subverting (come on, the rapist getting evirated and sodomized) in general is a pretty standard revenge manga with quite expected outcomes.
So i have my doubt that you pinpointing one specific character and situation is just a matter of...
We had a guy evirated and turned into a prison bitch and this last one cooking his own father alive.
"But the girl was forced into porn, that's too far 😫"
She got what she deserved, just like the other guys. And it suited her very well. She wanted to become a star, she became a porn star. Just...
I've certainly outgrown my "I'm not a kid mom, i read the serious stuff! Like attack on titans!"
And now i'm able to enjoy the edgy/sexy stuff without any trouble. If you still need to show off how "mature" you are, this mean you are still a kid.