The everlasting flame trick of the Baii family (of Da Xian)
"Stay still so I can make you my son-in-law and obey my orders." Jiang Si grabbed Bai Zhe's hair, making him look up. Bai Zhe was acting like he was in pain as if he was trying to fight the medicine. Jiang Si pressed his finger onto Bai Zhe's forehead before starting to write qi characters on his forehead one by one.
[Control.] [Slave.] [Loyal.]
"All right, use your blood and press it onto the characters on his forehead, child. Then, he will be yours," said Jiang Si; his daughter did as he said. She slit her finger until it had a wide cut before pressing it to every qi character. Immediately, the characters glowed.
"Ahh," Bai Zhe cried out in pain. He held his head in his hands painfully. His body was shaking. (It was all acting.)