Even if it doesn't obliterate it, it'll still hit through Flash Fire thanks to Turboblaze. Unresisted coverage in 2 moves off 170 Sp. Atk? 125/90/100 Defenses, well above average 120 Atk, strong secondary STAB in Ice Beam, and the potential to run Dragon Pulse, Roost, Focus Blast, Earth Power, or whatever the hell you want with Scarf or Life Orb seems too destructive and broken for OU in my opinion. The new Kyurem forms aren't terrible defensively: they can take hits pretty well and murder things with their outrageous STABs. White Kyurem definitely doesn't need to be in OU.