C903 History of the Flame King's Seal

"Young Master, if we don't want this Flame King's Seal, I think we can exchange it with Beiyang Castle."

Ning Cheng suddenly said mysteriously.

"Do you know what's good about Beiyang Castle?"

Xu Tianyu asked curiously.

"I really do know that. You should have heard of the mechanism technique, Tianyu, right?"

"Yes, the Mo family's mechanical arts are so famous