Although Zen-Aku seemed to have no heart at times, he did show signs of kindness when he protected a stray wolf and helped heal Alyssa's leg. He also showed signs of remembering his past, but General Nayzor put a fly in Zen-Aku's head, causing Zen-Aku to only answer to Orgs. His relationship with Jindrax and Toxica was not close, as both were jealous of his fighting ability. At certain times, Zen-Aku turned into Merrick when it was sunrise. The spell of the mask was destroyed when the rangers hit the Alligator head with the Wild Force Megazord, and Zen-Aku turned into Merrick permanently, as well as the Predazord's face turning from a wolf into a regular megazord's. When Merrick was Zen-Aku, the power of the mask was split between the mask, Merrick, and three Wild Zords. Even though Merrick was free from Zen-Aku, the mask was still intact and it revived Zen-Aku. He was more powerful than before, but he was still destroyed by the Wild Force rangers.