With the Lich King falling at this point in WoW we have officially killed, or beat the shit out of, every single bad guy, and good guys turned bad that were introduced in Warcraft 3 that weren't already dead and some of them did die in Warcraft 3 but just wouldn't stay dead.
Those that would die were suffering from an odd disease known as Kael'Tholosis resulting in death being a mere setback.
Arthas, never should have put on that helmet, he stopped killing powerful characters afterwards.
Archimonde x2, had to kick his ass in the past just for good measure.
Balnazzar x2, Something tells me we aren't done killing him yet.
Illidan, Imprisoned, released to help us, he helps us, we Exile him he goes to Outland, and then we go to Outland, find out hes there and kill him.
Kael'Thas Sunstrider x2, made comebacks cool
Kel'Thuzad x3, Why don't we just destroy his damn Phylactery already, how stupid are we? How many times does this guy need to die?
Kil'Jaeden, wack-a-moled his ass back through the Sunwell.
Lady Vashj, Killed her for stealing Water.
Magtheridon x1.5, Kick his ass as Illidan and put him in prison, then we decide to finish the job.
Mal'Ganis x1.5, Frostmourne couldn't kill this guy and then we make him run like a bitch to his homeworld, he even swears we will need his help to kill Arthas and the bitch never shows up.
Sapphiron x3, poor guy got his ass kicked by Arthas and then by us twice.
Varimathras, I always liked him but knew I would have to put him in his place some day, I don't think its the last time though, I smell a Dreadlord comeback tour.
I may have forgotten 1 or 2, I wonder if this means Warcraft 4 will be announced next that way Blizzard can have us kill all the new bad guys there in wow repeatedly until it isn't funny anymore.