Truth

"You instigated the fall of an entire family just because the girl you liked, liked somebody else?" Ning asked. 

Badel looked shook but controlled himself. "You are my father's guest so I won't say anything, but please don't go around spreading these lies," Badel said.

"Oh, if you say it's not true, then do you dare eat this Truth Seeking pill?" Ning asked as he brought out a pill from his storage.

"Wh-What's a Truth-Seeking pill?" Badel asked fearfully. 

"Of course, as it's named, you cannot lie after you've eaten this pill," Ning said. 

"W-What if it's a poison? Why would I eat this?" Badel said.

The Emperor looked at his son's scared posture and asked, "Son, did you really have a hand in the Gassain family's fall?"

"What? Of course not, father. Don't believe him," Badel proclaimed loudly. 

"Then let me ask another question. Why do you hide your cultivation base so much?" Ning asked.