One week before the ending of "Downfall", in Karda Nui, Tanma and Gavla were assigned to adjusting the "Scare-Rahi" (apparently a scarecrow-like object used for keeping away flying Rahi from the Matoran village) when Tanma noticed a large black flying creature heading for where Gavla was. When he went to help her, he discovered that she was different. She had been hit with a leech-like creature, and mutated into a monstrous form. She had become the first of the Av-Matoran to have her light drained and become a Shadow Matoran.