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.