If Dark Knight was good..

[Zairava]

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, hat he takes a lot mroe 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.

The absolute last thing I want on DRK is a bloodwhetting equivalent.