Originally Posted by
sevenflow
Before I get flamed to death about the double struggle for tanks I will exemplify the new rune system in a (quite common) tanking situation:
A Blood DK tank is in the middle of a bossfight and a pack of adds spawn. He has recently used his runes on tanking a previous pack of adds and his first set of three runes is refreshing as he runs to the new add pack.
He has 1 blood, 1 unholy and 1 frost rune almost ready, when these ready he will be able to use them and his last 3 runes will start recharging. The runes ready just as the adds spawn, the deathknight applies his diseases for free with his 1 minute cooldown and spreads the diseases to all the targets - using 1 blood rune.
Now he has 1 unholy and 1 frost rune, dots on all targets, but definately not dependable aggro on any of them, the one hes been white swinging might stick to him if hes lucky. He can cast a Death Strike on another target and possibly keep aggro on 2, but this pack of adds is 4-5 mobs unfortunately.
He doesnt have enough runes to cast death and decay, he couldnt have cast death and decay first, because DnD alone is not enough to maintain aoe threat and every DK knows this. He has to wait a full TEN seconds before he can get aggro on all the adds, ten seconds is more than enough to kill a handful of healers and buttonmash-happy aoe dpsers.
Let's say they compensate for this obvious design flaw by greatly increasing threat from Death and Decay. DPS DKs will be penalized by not being able to use it for DPS and it will completely trivialize DK tanking (Pop DnD -> /afk, great job tank!)