Deicide
Deicide is the killing (or the killer) of a god. The concept may be used for any act of killing a god, including a life-death-rebirth deity who is killed and then resurrected.
Also used in Freeman Dyson 's Disturbing the Universe in the essay "The Island of Dr. Moreau" when he is talking of JSB Haldane's Daedalus; or, Science and the Future.