overlay pressed—> animation of the chair starts
but this wouldn’t work everywhere in the map, so, I guess you’d have to trap the opponent in a specific place and then by pressing the overlay it animates the chair being thrown and after 5 seconds the opponent will experience some kind of damage. Giving the feeling of a chair attack.
Here is an animation guide, but if you can’t use it because it doesn’t have pictures, you could just use triggers and time delays, with props. I could show you it, just ask 
Anyways I think you found a solution, so be sure to mark one.