How to make a "Counter" Finisher?

Honestly, I just can't figure it out anymore; I simply can't work out how to execute a "Counter" Finisher. My problem is basic: I can get the Target to transition to the Finisher branch, but I haven't found any way to get the User to move to their corresponding branch. I really wish I knew a way to make the User enter the Finisher branch without needing a hitbox (since it's not a guaranteed hit due to projectiles, etc.).