This is Matoro "The Blacksnow", who could said to be the main character of Klaanon. At the beginning of the story he was an eager hero looking for adventures. He has become "darker and edgier" since them, after fighting Makuta Abzumo at a falling cathedral sphere airship with a black heart using one of the shards of Nimda, a powerful artifact with massive mind powers. He also lost his right (i guess) hand when fighting the dreadful Marionette (Coming soon!), one of Avde's puppets.
On his left hand Matoro now has a six-hooked harpoon. Especially at the first half of the story Matoro's harpoon was an important plot element, causing many daring escapes and unexpected (well, not really) survivals. In his right hand he has a mind-sword generated using a shard of Nimda.
And yes, the creation. The old version is here. When I saw "Kopaka, Master of Ice" for the first time, I knew the mask would look great on Matoro. Of course the old Akaku is a true classic, but the round shape didn't look that good on Matoro, and his mask isn't Akaku but Kanohi Cencord, prototype mask of mind in the story anyway (with added telescopes). New Akaku has a lower brow which makes it look edgier, a fitting detail with Matoro's character development during the story.
I also bulked up the shoulders, re-designed the torso armor and made some tweaks on the limbs; Boat studs make excellent back armor to Ben10 limbs with T-bars, by the way. I also gave Matoro brick-built hand to allow more diverse posing.