How about Riposte?

[Freyyy]

It's a Dark Knight ability. It triggers off Parry. When they parry, it activates the ability to use an Off-GCD attack (and in the case of FFXIV's riposte, it both does damage and applies a damage down debuff).

This Riposte idea looks more like WAR's Vengeance than DRK's Reprisal. If DRK's Reprisal is Riposte, PLD's Shield Swipe is too and even more since it can be done every time you block.

I think this stat would be a good idea as a replacement to parry.