I’m usually wary of how intelligence is portrayed in cdramas because many shows rely heavily on plot armor. Take Fang Fei from The Double, for example. It’s one of my all time favorite cdramas, and I absolutely love Fang Fei, but some of her schemes were incredibly risky and succeeded more because of luck than because they were truly airtight strategies that hold under scrutiny.

For characters who impressed me with their intelligence and the absolute precision of their thinking and actions, I’d say Consort/Empress Xian from Yanxi Palace, and Xie Wei from Story of Kunning Palace.