The Old King smiled, "Him? Very mysterious. I'm not too sure about his true identity, but his current identity poses no threat to us. He's a very capable person, researching many things. When you were gravely ill before, it was the medicine he developed that cured you. He has five subordinates, who are also quite formidable. Recently, I just signed an agreement with him for cooperation, so he and his five subordinates now live in the palace. However, I think you should not interact with him too much. If you anger him, I'm worried it will be troublesome to handle. But since you like him to teach you horse riding, Grandpa will give it a try."
The Old King's words explained Shangguan Xiu's identity and also reminded that Shangguan Xiu is not an easy person. However, in order to make his granddaughter happy, the Old King was willing to take the risk to test Shangguan Xiu, which showed that he genuinely wanted to make An Xiaomian happy.
