You lost me as soon as you said "retaliate 20% of damage taken" most people will read that and go "Oh I need to get hit by everything so I can maximise DPS! that makes me MLGPro"

So really what you are saying is you want DKs to be known as the tank that stands in every AoE that doesn't one shot them and to rage at SCH/AST for using all their healing abilities because shields will reduce their DPS by absorbing damage before it hits them and that's just in 4-mans.

I know that's not what you mean but I would be willing to bet that would end up being the case.

And in terms of "lore" isn't grit meant to be all "I will not die to you" kinda thing so mind over matter type deal? "grit - courage and resolve; strength of character."