positive disintegration

This is a mirror thread of this, and is inspired by the game Planescape: Torment, one of the greatest artistic and philosophical masterpieces in gaming to date. The title is true to the original form of the question, but I'd ask the same question here as I do in the sister NT mirror thread...

The obvious answer is castration. However, I am not looking for obvious answers, and the question should in fact be reformulated to reflect that, such as "What can change the nature of a person?" As some of you might be aware as soon as you see the title, this is inspired by the game...