Coined in Blade: Trinity by Ryne Renolds' character; Hannibal King, the term is often used to describe types of people the word 'cunt' simple doesn't describe well enough.
Thunder Cunt describes a person so cuntish that it is as if the
Thunder God himself had thrown a bolt of
lightning into an infected vagina, spread the
infection to the brain of said person, leaving them a disastrous, miserable, lonely peice of shit.
Thunder Cunt.