Khaine

Khaela Mensha (lit. meaning Bloody Handed) Khaine is the Eldar God of War and is one of the last living Eldar Gods after the fall of the Eldar, although due to him being trampled on and pushed into realspace when Khorne was piledriving baby Slaanesh all over Eldar heaven, he's no longer "alive" in a spiritual sense and is now shattered into a bajillion pieces. These pieces make their way into the Craftworld which can be used to summon the Avatar of Khaine when the time comes, an avatar is a towering daemonic creature that makes anything it can get it's hands on shit brix. He's also the angriest God of the Eldar Parthenon, which can't really contest with the likes of Angron and Doombreed but probably comes a close.

Myths

Long ago when the Eldar were the most powerful race in the universe and they haven't raped the entire universe yet, Khaine heared from Lileath, a prophetic chick, that the Eldar will one day kill him and so Khaine decided to murder every last one of the pansies to ensure that never happens. However Isha, the mother of the Eldar, cried for the Eldar race. Then Asuryan, the Phoenix King decided to spare the Eldar of being raped by Khaine and Isha having to see it by creating a barrier to separate mortals from gods for all eternity, ensuring the mortal Eldar would never have the chance to kill Khaine.

Isha however missed talking to her children and so cheated through the whole barrier deal by making spirit stones to communicate with them. Khaine however, overheared them and cried foul on Isha and her husband Kurnous. Asuryan not wanting to look like a biased dick told Khaine that he could do whatever he wanted with the two, which equated on eternal torture in the hands of Khaine, given the pasines of anything created by the Eldar, some suspect that this involved having something stuck up their orifices as Khaine enjoyed himself in a BDMS-esque fashion. Then Vaul got pissed at this and bargained with Khaine that he would make a thousand of his finest swords in a year in exchange for Isha and Kurnous' release, which he agreed to. However as Vaul decided to jerk off on the last day, he couldn't make the last sword and so tried to trick Khaine by putting one normal sword in the bunch, thinking that with Khaine's short attention span, he won't notice. He however didn't count on Khaine to be a total mathfag whenever he's weaponwhoring and so Khaine fucked over Vaul and tried to him an anvil.

Then he murdered Eldanash, an Eldar champion, in an unspecified incident that had Asuryan him condemn to have blood eternally drip from his hands to remind him of his crime which also earned him the title "Khaela Mensha" .

Then when Slaanesh was born, Khaine tried to fight the freaken and was, in the Eldar codex's words: "assaulted, defeated, and dominated", which sort of translates to being raped and forced into a buttsex-themed BDSM party. Then Khorne came down and challenged Slaanesh to a battle, which the latter lost. And while Khorne was busy piledriving and backbreaking Slaanesh into oblivion, Khaine was in the middle of this and got shattered in a million pieces, presumably because Khorne left his axe back at his Brass Citadel and Khaine was the only available meele weapon at the time, and the rest is history.