As well as corruption, another big fetish of Ty's was sex transformation. The idea of the supposedly immutable sexes getting switched around, men discovering how womanhood feels and women discovering how manhood feels, was really exciting to him.
He decided he'd make this fantasy come true by wishing into existence a new contagious virus. The virus would rewrite the body's hormones, causing the affected person's sexual characteristics to rapidly change. Men infected by it would have their penis shrunk to a clitoris, their testicles recede into the body and connect with a womb to allow them to be impregnated, their scrotum flattens and opens into a vagina, and mammaries and breasts form on their chest. When it affects women, their vaginal slits close up, their ovaries reshape into testicles and drop into a sac formed between the legs, their breasts recede into the chest as firmer, thicker muscles forms in the upper body, and their clitoris enlarges several inches until it forms a penis.
Besides all the physical transformation, there was one very important adjustment to people's minds: the change would massively increase the affected person's libido. Having spent your whole life up to this point feeling certain desires, they are completely reversed, and it makes them horny, lustful and desperate to have their new body fulfil what feels like a newfound biological purpose.
Just thinking about the changes was getting Ty excited, but he had to quickly decide who the virus's first carrier should be...