The rape of tens of thousands, slaughter of even more, germ warfare, terrorism, destruction of Baghdad, and all of his other horrific deeds doesn't strike you as evil?
I voted Genghis Khan. Easily one of the most vile and evil people to have ever lived, and probably does take the top spot.
Cool, except 800~ years ago that wasnt unusual. Thats like calling everybody a dumbass when bloodlettings were a thing. It is a different world. Those actions are not justifiable, but thats how things were... Hirohito was much worse in terms of virtually everything, directly or indirectly, but that was during the 20th century.
What do you mean it's a different world? Some things change, some things don't. Murder was bad then and it's bad now.
Khan ruled the biggest empire the world has ever seen. They killed everybody who wouldn't bow.