Get to the Point
Testing the steadiness of Changshou ,his wit and personality all in one ...that's smart . He's confirmed Changshou's innermost nature ,'steady' .This will confirm if his steadiness and wit would allow him to deduce this isn't from the sage ,and then his response to it- 1. Obey and show off appropriate might ,as per sage standard 2. Disobey and take it as a test of ones nature ,continue acting steady 3. Obey but remain in the shadows ,showing off might of Ren school through others while leaving himself away from karma Any of these 3 answers are already of excellence , but the third is the only action that I see would fulfill steadiness and obedience at once . This is a personality and wit test done cleverly , Xuandu and Changshou really doesn't disappoint .
Looks like Xuan Du has understood Changshou's true nature. Guess he's not the Great Daoist Master for nothing. While it seems like Changshou is finally on to him being the one sending the enlightenment. The question is, what he'll do about it. After all, he's not your standard xuanhuan male lead who'll tell him "go to hell, I do what I want!" and plot armor the consequences away. No, he has to listen and respond somehow, he'll never risk offending such a powerful figure and his long awaited backer over this. Fortunately, it didn't say he had to do it personally, just that the prowess of the Ren school needed to be shown. So I'm betting he's going to finally cave and go see how toxic junior sister is doing. It should be enough to support her and Lingli from the shadows and have them take the best rank in the contest, while remaining obscure himself. That's my bet at least.