Genghis motherfucking Khan
[1] Tada! The Wiki article!
Since Genghis Khan was a daemon prince anywho it figures accuaracy shouldn't be much of a problem here. They're already way off.
In short, He killed a ton of people (40 million to be exact, with bows, arrows, spears, really primitive rockets, blackpowder guns, and swords), made an empire (the biggest pre-space faring empire of all time, though it may be exceeded by the british depending on how far north you define it's borders as stretching), and became the first daemon prince of Khorne to kill a ton more people. We know Ghengis motherfucking Khan as Doombreed.
He is the most badass Asian of all time, because he killed 40 million people in a time before automatic weapons and conquered like 16 million square miles of territory in an age before motor vehicles. (His children and generals all went on to slaughter even more people and conquer even more territory, they all also became Daemon Princes of Khorne, with Genghis' greatest General Subutai becoming Khorne's greatest strategist who helps Khorne out-think Tzeentch along with Genghis)
Not only does he help Khorne outthink Tzeentch, he helps him outsex Slaanesh. Because in life, he fucked so many bitches that today there are 7 million people directly descended from him...So he is the greatest warrior and womanizer of all time. He also out-plagues Nurgle because it was his mongols who ended up spreading the Black Death that gave Nurgle Sapience. So in otherwords, he is so awesome that thanks to him, Khorne can beat the other three Chaos Gods at their own games.
Alternative spellings of his name include Changheiz Khan, Tchingis Khan, etc. His real name was Temujin.
It is said that an entire 2% of the World's population can trace their bloodlines to him. 2% of the world now worships Khorne.