i see no point for this in trash u should do a big pull rota so better buff the dmg from purgatory
Let me explain this with my perspective, as a mage/rogue you always need to use Kiss of the Vampire for maximum potantial damage, of course you can just use AoE skills for mobs. But then your dmg will not be so high. If you are playing with a strong raid, your AoE damage will always be lesser because mobs will die before you use Cursed Fangs + Kiss of the Vampire ( these 2 skills will take 1 second to use, but even 1 second is too much). And your overall damage will be lower.
That is why i am suggesting to use Kiss of the Vampire skill (ID:491345) without Cursed Fangs skill ( ID: 49158).
But of course this is my experience with mage/rogue. If you have a better idea, you can share it with us.