Dark Knight Question

[shao32]

OT always outside of tank stance no excuses, and is a overall dps loss stay in tank stance when OT the small gain you get from bloodspiller on grit Does not justify the 20% of damage penalty of the rest of you skill set plus blood weapon and unnecesary agro problems.

[Sylvain]

Not only you are correct, but your friend seems to forget that the -20% damage is applied to every skills.

So not only will it do slightly less damage than without grit, but every single skills and AA will also do -20% less.
And if he switches between grit/nogrit everytime he wants to use it that's also dumb. because he looses 2 gcd everytime he does so.
This is not considering the loss on the DPS cd too.

Well, in short your friend is extremely bad at math and you should never listen to him.