4.x DRK is sometimes framed as or suggested changes are made with the idea of making it an "active mitigation" tank because: A) if you're trying to bring DRK up to par with the other tanks defensively, you require the fewest steps and the smallest number of skill effect changes to center its defensive identity around TBN, compared to the 2.1-WAR-esque overhaul you would need to adjust its suite of traditional cooldowns to do the same thing, B) TBN is, in sort of a general sense, the strongest of three tanks' active mitigation skills: Inner Beast, and Sheltron in particular, are situationally better, but neither really has the flexibility or overall potential of TBN, C) It seems a little silly to have three tank classes who all handle their mitigation duties by scheduling out 'set and forget' mitigation tools that have long-ish durations and longer cooldowns, when you could easily change it up and have one class that plays very differently, D) It matches up fairly well with DRK's current offensive identity, which is all about using Dark Arts as kind of a per-GCD Berserk, and E) If you commit to making TBN the centrepiece of DRK mitigation, then there are a lot of creative and fun ways that you can build on to that, whereas adjusting DRK's other defensive cooldowns is mostly a matter of just going "Okay, make these a little bit more like the other, better cooldowns that the other tanks have".


There are definitely some big issues that need to be addressed with TBN, if it were to be used that way (For instance, the cooldown would need to be substantially shorter, so that its use is essentially governed by MP regeneration rather than a cooldown timer; it would need to be available at or before level 50 so that it's usable in "max level" content from each x.0 iteration of the game; the interaction it has with Blood is also kind of not-great and could be greatly improved; the specific way that MP converts to damage in 4.x DRK makes further adjustments really touchy; etc). But given DRK's current position, and the likely/realistic expectations that we can set for how much work SE is willing to do to address the class's issues, I think that going all-in on TBN as a defensive identity is probably DRK's current best bet.