Quick answer
What chapter does Imu first appear in?
Verified through chapter 1085Updated
What the manga shows
3 factsImu sits on the Empty Throne in the throne room during chapter 1085.
Imu addresses assembled robed men while in a wheelchair in chapter 1085.
Imu refuses to explain the significance of the name Imu in chapter 1085.
Change log
1 chapter- Chapter 1085Added 3 facts; updated the answer