Aiwei

Aiwei is Suyin Beifong's advisor and truth seer of Zaofu, detecting when someone was lying with his seismic sense. Because of this, he was the only person in Zaofu who truly could keep a secret, and used this as well as Suyin's trust in him to his advantage in order to help Zaheer and his gang into the city and kidnap Korra.

History
Aiwei was the first person to greet Korra when she arrived in Zaofu to search for a new airbender and to take refuge from Zaheer's gang. Aiwei was able to notice that someone was missing from their group, and after meeting Suyin she confessed that Lin was still on the airship.