Adam Dodd of season one of Survival of the Fittest swears vengeance against Cody Jensen after Cody's definitive crossing of the Moral Event Horizon, raping and murdering his friend Madelaine Shirohara and accidentally killing his love interest, Amanda Jones, in the middle of trying to kill Sidney Crosby. After drifting for a while in a Heroic B.S.O.D., Adam takes down everyone who tries to kill him one by one, and when Adam and Cody finally face off, Adam fulfills his vow of vengeance by putting a sword through Cody and then carving the word "rapist" into his chest.
One day, "God" reveals to all of humanity that the Pearly Gates are closed (and actually have been for some time), they're all condemned to Hell and he's even given Satan the okay to "wipe out" humanity (or rather, kill them and torture their souls in Hell for eternity). Humanity's reaction was The Salvation War.
Mortal Kombat Legacy has this for General Hanzo Hasashi (AKA Scorpion), after him and his family, along with his entire ninja clan, are slaughtered by Bi Han (AKA Sub-Zero) and his ninja clan. However, Quan Chi is the one who performed the deed and framed Bi Han, who actually wanted peace with his childhood friend, even after Hanzo was forced to kill Bi Han's brother in self-defense. When the two meet in Mortal Kombat, Bi Han desperately tries to convince the undead Hanzo that he wasn't involved. Hanzo doesn't believe him and rips out his spine.
Scratch from We're Alive goes on one after Pegs kills her brother, Latch. She swears to kill Pegs at all costs. And in pursuit of her prey she brings down the Tower with an RPG and improvised bombs made out of gasoline tankers, captures and tortures Burt to find out where the Tower folks are hiding, kills Angel, kills Durai and continues to stalk Pegs even after all the other Mallers are either killed or scattered.
In the AlternateHistory.com timeline A More Personal Union, Francis Drake's younger son is killed by a Spanish raid on their colony. Driven mad with grief, he and his older son dedicate themselves to leading pirate attacks against Spanish forces and colonies throughout the New World.