I’m not sure if matching their aggressive behaviour with equally aggressive tactics works…or does it? I don’t know. You tell me the results.
What about rewards like 8 year old children or puppies love (operant conditioning) You could start a smiley chart for each character on a board and reward good behaviour.
“If you are quiet and well-behaved today, I’m going to give you a treat. (example sticker, smiley or whatever works with that particular character)
Is this too weird a suggestion? 🙂