Victory Rush

You must actually get the killing blow for this ability to become available.

Correct me if I'm wrong, but this is a basically a free Bloodthirst for each mob when grinding, providing you attack a mob within 20 seconds after a kill (which is kinda self-evident).

You can only use the ability once for every kill, but since it's free to use and does descent (critable) damage it's a good ability. It will only light up if the player or mob gives an honor/xp reward. The only drawback is the need to use it fast. It's only available for 20 seconds, so it gives a feeling of "don't waste the opportunity". You will probably more often charge the next foe when it would be a better time to heal for example.