He starts with a few triggers

"Yang," Cardin said. "Be honest, you're faking right now, right?"

"No," said Yang.

"If you're not faking, say something nice about me."

"Cardin is so sexy," Yang droned.

"Hm," said Cardin. "I know! When you wake, I want you to forget about that little prank on Ruby. Whenever I say 'drop and give me' followed by a number and an exercise, you'll instantly do that amount of the exercise. So if I say, 'drop and give me ten push-ups', you'll give me ten push-ups. You'll be aware of your actions but be unable to do anything about it."

Cardin thought a bit more.

"Also, if I say 'The truth is' followed by a statement, that will instantly come true in your mind. Unless the statement brings direct harm to you or someone you love. I'm not that sadistic. So for example, if I say 'The truth is you're supposed to smack your ass every time you finish a sentence' you'll start smacking your ass after every sentence."

Cardin then realized he probably needed to go somewhere contained.

"Follow me to my dorm."

The mindless blonde marched after Cardin back to his dorm. His teammates were away right now, so it was just him in the dorm, with the hypnotized Yang, of course.