Consider ditching the animation for this ability, and exchange it with something akin to Shield Charge with a smaller cone of effect (i.e., an attack that allows a variable minimum range, even point blank). Staff Lunge is too awkward to really use, with its substantial minimum distance and long animation time. Trying to hit a moving target is very difficult, and it's always a huge DPS loss if you try to use it as anything but an opener (due to long animation). The Shield Charge animation is just so much more user-friendly and effective.
Edit: clarified as Shield Charge instead of Shield Rush