Nie Huaisang

Niè Huáisāng (聂怀桑) was born as a young master of the Qinghe Nie sect, was later on given the title The Emerald and eventually joined Wei Wuxian's Imperial Harem.

Personality
Nie Huaisang often puts on a facade and acts like an oblivious and foolish youth who's only interested in art, fans and birds but not at all in cultivation or studying, which is why other people are quick to judge, overlook or underestimate him.

Beneath his facade, he's actually insanely smart and cunning and can be very manipulative and observant, which is supported by the fact that everyone underestimates him.