Two major points:
- Triggers off buffs as well as debuffs.
- Appears to loop itself to an extent I’m not quite sure of – sometimes it kills everything, sometimes all but one. Either way it’s triggering far more than a max of five or six times, and is entirely capable of hitting the initially attacked creature repeatedly. Double tap looks like the description could imply it, but it looks like it’ll cheerfully hammer the main target more than twice. It also definitely hits things besides the main target repeatedly, which doesn’t seem at all intended.
Minor point, is it actually intended to be Square Nothing? Because spare makes a bit more sense, heh.