So, if you interrupt Life Hunter at the perfect timing right after the chan bar is through and before the skill animation starts it still deals both strikes of damage. That basically cuts the total skill-execution time to ~40% of the original. Heck, it's even so broken that if you have perfect timing and chain Condensed, Spell Cutter or any other fast skill that it will count those 3 hits as one and give way for nice charm-bypass combos.
Granted, it is tricky to pull off and messing up the timing could lead to deselecting your target. But still, why is no sin using this? That's pretty OP. Yeah, lag can **** you over quite a bit I guess but that applies to pretty much everything, hehe.