Yawak

Yawak is a former Toa of Plantlife, and a member of the Blood of Karzahni.

Toa Hagah
Yawak was initially a Toa Hagah under the command of a very minor Makuta. During Teridax's revolt, Yawak joined the Makuta and killed his Toa Hagah brethren, shocking all other Toa. During Kojol's raid on Artahka, Yawak helped. After learning all those who went on the raid were being killed, he made a run for it.

Fleeing/Mutation
Being a Toa, Yawak could usually get by without being overly noticed by many Matoran outside of small villages. During a boat ride to an island, as he was constantly moving, Yawak encountered another hardly notable Makuta, who mutated him, causing him to have no powers over plantlife, but amplifying his mask power, along with his speed and strength.

Blood of Karzahni
Yawak's mutation caused major psychological damage for a time, causing him to just let his boat drift. He eventually landed on the Blood of Karzahni's island, greeted by Aspak, back from a mission, who ensured he joined. Once joining, Yawak didn't feel quite as depressed anymore.

Spherus Magna
On Spherus Magna, Yawak led an assault team on New Artahka.

Abilities and Traits
Yawak has enhanced speed and strength due to his mutations. His Mask power allows him to keep his weapons sharp enough all around to easily pierce Makuta Armor, making him a threat to all those he fights. He shows zero mercy to any Makuta, due to a grudge borne against his mutation, or Order of Mata Nui member, due to them sending him on the run. Otherwise, he is a relatively nice and calm individual who enjoys sword fighting for entertaining himself.

Tools
Yawak knows how to use his incredibly sharp weapons to optimum ability, often jabbing in with the smaller knife, then removing the arm that tries to stop it with his staff.