Virtually all of the swear words in Quebec French come from altered pronunciations of words related to the Catholic Church.
The expression s’en crisser is one such example:
Je m’en crisse.
I don’t give a damn, or even
I don’t give a fuck.
The verb crisser in this expression comes from the name Christ in French.
[This entry was inspired by the character Kim in Mauvais karma, “Ça fait désordre,” season 1, episode 1, Radio-Canada, Montreal, 8 September 2010.]