PLATEFISH'S PROFILE

Alright, I'm new to this whole battle system thing. I just wanted to make a quick battle, as simple as can be, but the enemy doesn't attack right. It says "you attacked the enemy" at the top and then the hero just keeps taking damage until he dies. You can attack while this is happening, but the monster never stops attacking him. I guess this must be a basic question, as I'm just trying to get the built-in characters to work properly but I can't get it to make a proper turn-based battle. I apologise for not including any information, but I have no idea what could be causing this to happen. I understand my explanation is pretty shaky so here's a video of what's happening
Thanks for reading, sorry for the probably basic question. I just want the enemy to attack once.