I think by the end Consort Jing was my forever fave.

For me, my favourite Mei Changsu manipulation moment was when Jingyan was organising the tents and blankets for the people affected by the factory explosion - and MCS tells him not to make a formal report about the military goods he requisitioned to see is the Crown Prince tries to pettily use it against him. And he does. And it makes Jingyan look GREAT.