One time I made a Touhou OC loli sex doll who was violently destroyed by everything that fucked her.
Dinah was one of Alice's dolls that she made as a sex partner, but eventually stopped, and turned into a youkai through sufficient neglect and sexual frustration. I had a huge backstory written up for her, and even explained why she was basically a sex demon that ambushed humans and other youkai to fuck them, basing her power on the Taoist beliefs that ejaculation released sexual energy (jing) which she converted into life force (qi). She was, essentially, a three foot tall vampire sex doll who literally needed to be cummed in to survive. Despite being a Touhou character with a Rozen Maiden artwork, it was actually my most original character in terms of concept and writing, and I loved actually writing the backstory and lore almost more than I did playing her.
I only ever did two roleplays with her. Since she was a doll, there were plenty opportunities for me to explore some darker kinks that I'd never do with a human character. In one, she got facefucked hard enough to literally shatter her face from the impact, and in the other she was gang-raped by monsters and filled up with so much cum that she exploded.
I've never done anything so extreme with any other character, and never would, but to tell you the truth, these two roleplays were the best ones I've ever done.