I know DTs are getting a heavy Nerf Bat, but those nerfs do not effect one seriously broken mechanic; Mana drains. DTs can spam Mystical Bane, making most casters virtually useless. To make a caster (especially a ToS which I main) go OOM, a DT needs to use two ranks of Mystical bane and a Seal of Chaos to completely shut them down. ToS in particular have mana regenerating spells / feats, but they do not help enough to compensate.
The nerf I would like to see would be to make all Mystical Bane ranks share cooldown, that way the DT can only use one rank. Another idea(and perhaps even better) I have heard from guild members would be to make the mana drain portion of the combo on a cooldown that shares duration with the cooldown of the combo, that way you can only drain mana once even while using multiple ranks.
Please don't take this suggestion harshly DTs, even you must know how broken this mechanic is.