I've held my tongue long enough. The reason your topic don't tend to get much traction is because, quite frankly, your ideas are not well thought out.

in this case, using HP for damage is not good and your physical tank buster mitigation is a death sentence. However, to go over things here and from other topics in the same vein, tying damage to defensive tools just turns that defensive tool into something offensive. You won't use it for defence at all. In the case of Warrior's Vengeance, it is weak enough that it effectively has no effect on your damage, it is literally flavour and as for TBN, that is using an offensive resource where, as long as the barrier breaks, you end up DPS neutral at worst.

As for your ideas on the different tank busters, why? What purpose does this serve other than button bloat? You mentioned in another topic that it would be random whether the boss does one of the 3 types. You cannot plan anything around that, especially with the party mitigations you want to put on the magical busters and damage you want to put on the physical. The mitigation has no guarantee of being used and, especially if it is random, is not something you can rely on. As for the physical one, again, randomness in how damage is dealt, does it happen to line up with burst phases? What if I get tons of them one run and none the next? You are just asking for a tank's DPS to fluctuate wildly from run to run.

As for what you have here, as long as you survive the hit, you have effectively given DRK a 30% damage mitigation on everything. That is stupidly strong for anything. Plus, you negate any sort of shielding that takes you over max HP. The whole point of shield to to give you more effective HP, by not allowing them to go over 100%, you make healing as a Scholar or Sage that much harder for no reason. Even the shield granted by WHM and AST would be almost useless.

As for Flood/Shadowbringer. What does it effective achieve by converting HP into Darkshield? You have the same HP, why go though that, oh wait, it's Eventide, the thing that, if used to the max potential, will kill you. It is also worth noting that your graphic for Frey's Blessing is wrong. If you start at 30% HP and it heals 20%, you will be at 50%, not 65%.

And now Shadowed Vigil, Reduce damage taken by 40%, but only with 3+ enemies? So it's either useless in boss fights or it is weaker (assuming old 30%). Either way, what is the point in that?

Again, your ideas are not thought out in the context of the game. I also see you mention that this system has been used in other games. Are they MMOs and does the combat play out like FFXIV. If either of those answers is no, then you cannot just take it from one game and hope it works here. Different systems and different game genres mean different mechanics and things to think about.