General

Infinity strike skill?

My reverse warrior helm got +1 skills, one of which is for infinity strike. I've never heard of and can't find anything about it. What class has it? If it helps, the other skills are:

Rush (adventurers)
Overswing (aran)
Infernal cuncussion (Demon slayer)
Radiant Blast (Mihile)
Infinity Strike. It seems like it should be for kaiser, but as a kaiser, not of my skills are affected by it, unless it's supposed to be blade burst, expert sword mastery, or unbreakable will, as I have those maxed.