Which individual in all of history killed the most people?

The person which killed the most people, with his own hands. He didn’t order, or make someone kill the person for him. Who was he?

Single-handedly? That title would have to belong to Simo Häyhä a.k.a the white death (yes, that was his nickname). He was a Finnish sniper during WWII who became a legend(he is widely considered to be the most skilled/deadly sniper that has ever lived). The Russians feared him so much that they've put a bounty on his head. After all he had over 500 confirmed kills. One man, responsible for the death of that many Russian soldiers, that was something that they couldn't let slide.

This is what he looked like: (after a Russian soldier shot an explosive bullet into his jaw, literally half of his face was missing upon impact, but somehow he managed to survive that attack).

See his picture here: QUORA