Parry haste

Initial analysis of all the data we have shows this behavior for NPC parry (the blue line is time remaining on swing, the orange line is the haste):

Player parry seems to follow the same rules (we don't have nearly as many data points though so it's noisier):

In summary:

If time remaining > 60%, reduce by 40% of speed
If time remaining < 20%, no reduction
Otherwise, reduce by (time remaining - 20%)