[DRK] Wanna know why Unleashed & Abyssal Drain are both needed?

[LordHousewife]

Souleater is the closer on a three part combo. Hitting nine would allow you heal just as much in a single GCD, or three times as much in three GCDs. That would be a very significant heal without DA requirements.

Yeah if you have 9 enemies it's really efficient. If you hit 3 in 3 GCDs you just spent more mana than you would have on DA Souleater and healed for less overall. I don't see the problem with it either because it's not significant enough to be considered broken.