making a jujutsu kaisen style game in roblox studio, abilities wont hit

nine times out of ten this is hit detection running on the client. the hitbox you see on your screen doesn't count for anyone else. fire a RemoteEvent when the move is used, then do the actual hit check on the server, something like GetPartBoundsInBox or a spatial query around the player, and apply damage there. .Touched is really unreliable for fast moves too, it misses a lot. also check you're not hitting your own character first and stopping the loop