Varien and his wifeWell apparently no one fucking dies in Warcraft anymore, whether it's demon, demon hunter, human or other. Then again we had shit like Altar of Storms all the way back in WC3 where you could resurrect heroes for the modest cost of a few hundred gold.
Look at Uther, we contacted him during one of the artifact quests and he was like hey guys wassup, so everyone's spirit is somewhere ready to be accessed at your heart's delight and stuck into a physical shell.
Fucking Archimonde died in at least 3 separate timelines already and the motherfucker still comes back like nothing happened.
Medivh on the other hand was a Guardian, resurrected by a Guardian, bound to a magical tower that transcends dimensions, past-possessed by a Titan, all kinds of shit.
The guy can do whatever the fuck he wants, even if he dies he'll be back somehow if he wants. Wish they'd followed Warcraft 3 lore and let him be a "legend of the past", but after Warlords of Draenor I've realized they'll even bring back Anduin Lothar if it suits their nostalgia purpose.
As long as there's a planet somewhere with a bunch of motherfuckers with some magical competency they'll just cast some kabbala voodoo shit and summon back Arthas to fucking Aman'Thul himself.
Shit's getting out of hand.
Arthas
Terenas
Garrosh
Rhonin
Mu Guldan
both blackhands
MU marad and yrel
Anduin lothar
shall i go on?