Azshara is the Smartest Villain in WoW

Azshara throughout history has being doing the most ingenious plan; she's playing the long con. She dedicates enough forces to any major threat to Azerorth to keep them off her back while not taking the brunt of the damage and not having the focus on her.In BC she sides with Illidan but only uses the fraction of her power to keep Illidan on her side so he can basically distract the powers of Azeroth.In Cata she sides with the Old Gods and Deathwing and does the same; dedicated enough forces to be allied with the big evil while also keep herself away from the central action.She's doing it again in Legion with the Burning Legion. She is basically subtly manipulating both us and the major evils in the universe to destroy and weaken each other so one day she'll have little to no resistance and finally take over.This is the theory that makes the most sense to me. She's not involved or using her insane power because she's playing everyone.