Protip: If you see Archmage Vargoth out in the broken isles, talk to him. He'll give you a 30% damage buff for one hour.

He's one of the mage combat allies. When he's summoned he'll linger for about 3 minutes. He's on a 5 minute cooldown so I like to drop him by flightpaths or emissary turn in NPCs.The debuff disappears if you leave the broken isles or go back to dalaran.