Nega-Catboy

Nega-Catboy is the 2nd episode of Season 15.

Summary
Catboy is affected by Lady Rancora's negative wish energry and  fills with negative memories just to turn  his back on his friends, making him think that they are his enemies instead. But while affected, Catboy learns to let go of all the bad stuff he has done in the past and not think negatively.