Nokama

Nokama was introduced to the Bionicle universe as a Turaga on the island of Mata Nui. It was later announced that she was a Toa of Water on Metru Nui, and when she was a Matoran she was a teacher in the village of Ga-Metru. During the Visorak invasion of Metru Nui, she was breifly a Toa Hordika but was returned to her normal form by Keetongu.  

Visorak Invasion  
When the Toa Metru returned to Metru Nui, they discovered it was covered in Visorak webbing, the creatures having occupied the city when they were gone. The Visorak had hunted the rampant Rahi down, mutating some, and stored the Matoran spheres within the Coliseum. From the Coliseum, Sidorak and Ruudaka ruled the Visorak Hordes. Having seen the new horrors running wild through the city, such as malfunctioning Vahki, infected Rahi and wild Rahkshi, the Toa decided to enter the Archives to rescue the sleeping Matoran. When they encountered an injured Ash Bear, Nokama proposed an experiment to use a portion of their powers to heal the beast. The Toa continued on, but when they exited the Archives, they were ambushed by several Keelerak and taken captive and brought to the Coliseum. After the ambush, the Visorak carried Nokama and her team inside. They were then suspended by Visorak webbing, coccooned and injected with the mutating venom of the Visorak. This made the team into Toa Hordika--half-Toa, half-Rahi creatures. After the mutation was completed, the Toa's webbing was clipped and the coccoons plummetted to the ground, to certain death, but were caught at the last moment by the Rahaga. The Rahaga brought them to Ga-Metru and explained that the venom had to be neuralized, or else they would remain Hordika forever. The Rahaga also told them legends of a legendary creature, Keetongu, a mythical Rahi that could reverse the poison's effects and make them Toa again. However, the team decided that rescuing the sleeping Matoran was their first priority, and looking for Keetongu could wait.  
Nokama was formerly the most peaceful of the Toa Metru, but even she had trouble controlling her violent new Rahi side. She found the warnings of her mentor Rahaga Gaaki to be counterproductive to her mission, and the newfound closeness to the natural world thrilling. Concern started to develop in her for the welfare of various Rahi, namely the Razor Whales being killed and/or captured by the Visorak Boggarak. She started also to enjoy some types of destruction, when she had previously loathed it.