Come to think of it, what if the affix affects enemies, and not the players? The description is still kind of vague, and I think that would make more sense. Would either promote taking down adds by one by one, or saving a bunch of burst aoe abilities to take out a pack quickly. Still would have issues in tyrannical however, as you could get a boss down to 10% and all the sudden it just destroys everyone.
Edit: Just remembered raging already kind of does the same thing, so either it gets replaced or this affix does indeed affect players.