An expression inspired by the 2005 internet fad around the Harry Potter and the Half-Blood prince in which the character Snape kills Dumbledore.
"Snape killed Dumbledore" is closest in meaning to shit happens or I don't give a shit and is is used as an unsympathetic comeback, similar to Jesus wept.
Guy 1: "Balls. I just failed another Calc test. Another, and I'll fail the class."
Guy 2: "Snape killed Dumbledore, you know? You always complain about failing classes, why don't you study for once?"
to kill a loved one or some one of great trust to trick your evil over lord to believing you are their right hand man only to help their enemy over throw them.
Kilo Ren snape-killed his father to trick smoke in to believing he was his servant.