Brainwashing

Brainwashing is a form of mental programming and manipulation that causes whoever is subjected to it to obey the commands of the person that are in control of the victim.

Empath: The Luckiest Smurf stories
Empath was subjected to brainwashing at least a few times in his life. At one time, he was mentally manipulated by Princess Chamelianne into obeying her and King Bullrush when he was being magically transformed into a Wartmonger. At another instance, the pixie Scullcap used an altered form of pixie dust to make Empath easy to manipulate so that he and Periwinkle could be framed for attempting to steal more pixie dust from the kingdom of Pixitopia.