You take the mask, you save the universe, otherwise I'll do it myself for the better. Matoro before he sacrifices himself
Matoro is a Toa of Ice; he sacrificed himself diminishing Jaller's Toa team to five.
Matoro was also the former leader of the Seven Heavenly Virtues until his ultimate sacrifice, leading Vriska Serket (Who also represented Humility like Matoro before her) to take his place.
History
Matoro was a translator, he was very quiet and very secretive towards the rest of his teammates. Despite that, he was still protective of the other five. Matoro always had an inferior feeling towards the other Toa. As time flew, he gained more confidence and began to take control of the team as they journeyed into the toxic ocean generated by Tsunami.
Out of everyone, he was willing to sacrifice himself because he wanted the other five of his teammates to live; thus putting on the Kanohi Ignika, Mask of Life so he can save Mata Nui and teleport his team back to Metru Nui.
After Matoro's sacrifice, there was no way Matoro could be resurrected ever again.
Known powers
Matoro is capable of freezing others and using the Kanohi Tyrna to control dead bodies; meaning he's pretty much a necromancer, but a heroic one unlike say, Googolplex.