Fixing Dark Knight, Properly

[Kabooa]

This is why Despair doesn't become a loss until the third consecutive use of the skill.

Your standards of "If this isn't absolutely DPS-optimal, then it should not be in the game" are, similarly, absolutely laughable. Apply that standard to every other tank skill in the game, and you suddenly lose every single tank stance, Clemency, Equilibrium, Passage of Arms, Inner Beast, and... Wait, look. There aren't any Dark Knight abilities on that list besides the universal tank stance. That's weird - must be a coincidence.

It's a DPS loss at the second use -because the first use is a DPS gain-.

You only have to look at how people regard tenacity to see why this is a problem.

(For the record, people avoid almost all of those like the plague -unless they're going to die-.)