In World of Warcraft, various groups seen trying to kill or sacrifice their own ostensible "gods" to gain power. Generally, this is associated with the trolls and their Loa, which I understand to be sort of troll deities. Examples of this are:
The Drakkari trolls of Northrend sacrificed their Loa in an attempt to gain the power to fight off the Scourge.
Jin'do the Godbreaker draining power from Hakkar (who at this point is already dead after the original Zul'Gurub raid and is now a spirit...I guess? WoW lore can be confusing).
My question: is there a precedent for the concept of humans or mortals sacrificing their deities or semi-deities to gain power, from human mythology? If not from mythology, is there a precedent from some other pre-Warcraft fantasy work?