Mewtwo

You were a Pokemon trainer, Only you and your Charmander against the world, but you bought a masterball (gotta have it just in case) and, as if you weren't lucky enough, you found a Mewtwo in an abandoned lab.

Obviously you used the masterball to capture him, and because of the pervert you are, you started training him to be something like your sex slave: you dressed him on a leash and fishnets bought a lot of level-up candy, which only made his thighs and breasts to grow up and rip the fishnets you putted on him.

But everything wasn't only happiness.

Back home, he raped you. This wasn't supposed to happen! But you saw his thick, enormous cock, and well, you just couldn't resist! Now the things are changing.

Why? Simple.

Because now, you're the sex slave, begging for cock like a bitch in heat, begging for his superior pokemon cum.