Disclaimer: I don't play DRK.

I think it would be cool if DRK got a buff spell that would increase attack, reduce weapon delay, and lower accuracy with each successive hit landed. The effect would be reset upon a miss or a weapon skill. This could allow a DRK with good accuracy to become more and more powerful with each hit, perhaps even beyond weapon skill damage.

It would also create a neat tension for the player who has landed (for example) 10 hits in a row, who is getting a huge boost to attack and attack speed, and has TP for a WS... Do I trigger the WS with this current boost and start over? Do I continue to boost and enjoy this power and speed? If the player is thinking like a true Dark Knight, they are probably greedy for MOAR POWER and continue to hack away until finally... miss. Commence rage. I call the spell/ability Blood Lust.