Spirit of the Merriasumus

You are able to wield the power of the Merriasmus. As an action, you can change a naughty creature into a nice one by forcing them to role a wisdom saving throw. On a successful roll, if a Toy creature or a creature from the North Pole is the target, permanently convert them to Nice and the will act as an ally. For non-North Pole/Toy creatures, they are stunned until their next turn. Nothing happens on a failed save. 

Per long rest, you can do this up to the same number of times as your proficiency modifier.