Since Math was asked for earlier...
https://forum.square-enix.com/ffxiv/...=1#post5778466
I very much doubt my feelings on TBN will ever change. It's a really, really, really good shield against single hit Tankbusters with no real follow up. I don't dislike the skill. I think it's unique to Drk and should stay, as I feel it is a part of it's identity now. But it definitely needs some tweaks.
Where it starts to really falter in my opinion is when you are getting hit with a Tankbuster that repeatedly strikes you over and over again. Or, in a dungeon where you have multiple packs ( 3 + groups worth of pulls ) hammering on you over a period of time. TBN on average breaks on the first strike of most multi hit TB's I've encountered. Or breaks extremely quickly in a massive dungeon pull. ( Usually within 2-3 seconds avg if I am doing a massive pull. )
A shield that crumbles in one GCD, cannot resist further hits, as it no longer exists. And Oblation as a level 82 skill is a pale comparison to HoC, Holy Shelltron, and Bloodwhetting. Even when Oblation is paired with TBN, it still will not hold up in comparison to those newly forged skills.
How to fix it is a conundrum all it's own.
Personally, I want TBN removed as the primary source fueling Dark Arts. I'd like to see Dark Arts revamped and other skills be used to fuel it as a resource, to keep Dark Knight's rotation more frequent instead of one, massive, overwhelming burst, and then a boring period where all we do is 1,2,3 until we have resources again.
Remove it's tie to fueling the damage, and maybe then other things can be added onto it to help bump it up a bit.
As for Oblation itself...I think the issue with why they placed it at 82 is because it can be slapped on another party member. Or so I would say, if it weren't for the fact that the same can also be done with Heart of Corundum.
6.08 is supposed to be a job patch based on what has been said of late. I didn't see any references to Dark Knight...but...am hoping they correct some of the major problems with the job. We'll see. Time will tell I guess.