Lunar Wolf Ranger

3,000 years ago, after Animus fell against Master Org, Merrick stole the legendary wolf mask and three Wild Zords from Nayzor, and used them to defeat Master Org. However, he did not remove the mask in time and was transformed into the Duke Org Zen-Aku, only for him to be sealed by the five original guardians before he caused trouble.

In the present, Nayzor released Zen-Aku, with no memory of him being Merrick. However, the Rangers freed Merrick from the wolf mask's curse, and he joined them as the Lunar Wolf Ranger.

Example of:
Sixth Ranger