As much as I love the idea of a Dark Knight being a Tank, I'm actually kind of shocked that they supposedly don't have ANY abilities that utilize HP. I mean, it doesn't make sense as a primary mechanic for a Tank, but I wonder if we might see something similar crop up for playing Solo, or even for the Off-tank role?

For example, after the Dark Knight's target is dead, maybe he can sacrifice his HP to help bring down the actual Boss quicker, or even just out questing, letting you convert your health into raw damage for faster, albeit riskier kills?