How is the whole thing evented? Is it really as simple as assigning a skill with a common event and calling a Force Action in said common event? I didn't see any problems with that.
Also realized bug: You are aware that when you target an enemy that is no longer alive the game chooses another target for you? Let's assume there are enemies A, B, and C. Should you happen to use this skill of yours on enemy A who is dead, the game chooses B to attack. But the last target index still points to A. Thus, when your force action skill is called, it can still hit B again.
Today is massive cleaning and chore day in preparation for a Father's Day gathering, so I won't be available to help. :\