Well we lack burst, so it should get buffed imo, thing is its 10 min cd, for a burst i dont see the reason.
i would like to have a 5 min CD on it and reduce ERW to 3 min.
so on long fight we get off two.
Keep the damage as it is or maybe give it a LITTLE buff not a major but a burst that is noticeble, just like other classes they got things with burst that scale, it should scale just like that.
And finally remove the cost of the use of it.
Or B remove it all together and give frost and unholy DK:s hysteria as baseline ability.
but only useble on yourself and increases all damage done by 20% counts as an ability not usable inside arenas for balance ofc, and no you cannot use it on other players.
This would solve it, and i think if going with B, frost should have a passive than for unholy, due to the fact unholy bursts way better than frost.
give a passive in the tree or inside might of frozen wastes that makes it gain somthing, 5-10% dmg increase on hysteria usage.
cooldown on it should be either 3 or 4 min.