From the Ashk Setting Guide

Klévo is also known as the Keeper of Secrets. The god of mischief, the jape, and the jolly prank.

He was damned because he convinced Tráxico to divulge his True Name as part of a trick. Malus overheard the exchange and used the knowledge to kill Tráxico.

For this, Klévo was banished from the presence of the other gods.