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, 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)