My guild just recently started progressing on Mannoroth mythic. We use a 3 mage setup for soaking the Wrath of Gul'Dan. Us three mages are all specced into arcane. But I see alot of other guild their mages are going frost on this fight. So to my question which one is the "better" spec for the fight? Or is it just personal preferens? I can see why frost can be better, there is nearly always a target to cleave on (expect the last phase), you got more movement with the instant procs you can cast.
But Arcane got a better burst in the last phase.
Is not that we need damage on the imps we got 2 Demo locks handling them.