If Dark Knight was good..

[Arohk]

Yep youre right, remove TBN and put a shield on Oblation and give it at level 70. Tanks clearly can't have anything unique anymore or any rewards for good mitigation, just do your 1-2-3 combo and spender forever.

TBN is not mitigation, it is a shield.
You can see that every time you have a Dark knight as a Tank in a dungeon, that he takes a lot more damage than any other Tank.

YOu can use 2-3 TBN per trash pull, which equals to 75% health , compare that to Bloodwhetting which not only gives you 10% mitigation and heals you for ~300% health on each use.