Olisi

The Kanohi Olisi was the Mask of Alternate Futures. Its power allowed its wearer to make himself and others view alternate or possible futures. The Great Beings created the first and only Olisi, which Karzahni received after he failed to defeat his brother Artakha for the right to wear the Mask of Light.

Karzahni wore the Olisi alongside his other equipment, which included Flaming Chains and gauntlets of energy. After he was exposed to the Pit's Mutagen, his mask became fused together and even more unrecognizable, and grew bulkier.

Karzahni used the Olisi against the seven Matoran who came to him while traveling toward Voya Nui. When Karzahni demanded their masks, Jaller refused, and in response Karzahni used the Olisi to show Jaller a future in which Teridax had conquered Mata Nui rather than being thwarted. Shaken, Jaller surrendered his mask. At Matoro's provocation, Karzahni later gave the seven Matoran a vision of the death of Mata Nui, an image so disturbing that it made even Karzahni himself hesitate. Jaller's group seized that moment to climb into the Toa Canisters and escape.

The mask was also turned on the Toa of Air Lesovikk, who had attempted to ambush Karzahni from a sea cave. Karzahni placed Lesovikk into a vision of the day his teammates Nikila and the others had died, except that in this illusion they had survived a battle with a sentient acid cloud and remained together. The vision included Lhikan, who in that alternate timeline would have met the older Toa and been offered a place on Lesovikk's team. A mention of the Zyglak returned Lesovikk to reality.

During the conflict on Voya Nui, Karzahni shattered Toa Tuyet and assaulted both Teridax and Matoro with the Olisi. Teridax retaliated and defeated Karzahni before being attacked in turn by Brutaka.