Absolute zero

Anyone know how this skill works? Found it in a book chest but it only has 30% hit rate and says its a supplementary skill. Anyone used it before? Worth keeping?

Thanks for reading!

[Koenaj]

It will kill the opponent in a single hit, no matter the HP/def.
Works the same as Execution.

I've had good experiences with it on my Clawpard, I found Blizzard was getting me killed in Ladder and Absolute Zero saves me often enough in PvP when facing OELs.

my fenrir use absolute zero to kill mino lvl 80 in BL15