You want the player to respond to pressing action (X or SPACEBAR)? It's super easy.
Edit[ Action Player | Sheep ] -> [ Action Player | > Sheep ] [ > Sheep | Sheep ] -> [ blood | > Sheep ]
You must feel so powerful now that you know how to ACTION.
It's treated like a directional input, merely one that has no effect during the movement phase and is removed (so if you search for a moving player, it will detect someone doing an action. If you want to detect someone moving who is not doing an action, you can use the word ORTHOGONAL (which just means up/down/left/right).
Action markers are discarded during the movement phase.
So, what are you going to use the action button for? It seems to want to be a button for violence, and puzzle games mostly get by just fine without it, but maybe you have some awesome ideas :D