As Gavla and Tanma were planting scare rahi, Makuta Chirox attacks them from the sky by launching a Tridax Pod at them. Tanma dodged but Gavla was struck by one of the Shadow leaches, which turned her into a Shadow Matoran. Gavla then attacked Tanma until the Matoran fled. Gavla was later appointed the leader of the Shadow Matoran. She was later present when the Makuta Phantoka battled the Toa Phantoka after the Battle of the Shadow Leach Hive. She did not appear again until the battle of the Codrex where she was riding Vamprah. Icarax struck her with a bolt of Shadow making her fall off towards the Swamp waters. Luckily Gorast saved her and returned her to Vamprah. After the battle was over Gavla was captured by Takanuva and cured by a Klakk. She then attacked Takanuva for curing her, stating that she prefered her life as a Shadow Matoran. She then journeyed to Metru-Nui with the other Matoran of Karda-Nui.
Gavla and the other Av-Matoran made it to Metru Nui and celebrated Mata Nui's awakening in the Coliseum when they heard Teridax proclaiming to have become the Great Spirit, and that now he ruled the Matoran Universe. The Matoran then scattered then separated to avoid being captured by Teridax. It is unknown what Gavla did until Teridax landed on Bara Magna.
During Teridax's fight with Mata Nui on Bara Magna, the blows that Teridax received created various earthquakes, and these caused the majority of the Matoran Universe population to be evacuated in shelters. Thanks to this, after Teridax's head collided with Aqua Magna, Gavla and many other Matoran and other beings were able to survive. As Teridax was killed by the impact, the Matoran Universe had three days before it ceased functioning, turning it into a world with no light, heat or air. Gavla had to join the mass exodus to escape to the reformed Spherus Magna. She is currently residing there.
Powers and Weapons
Being an Av-Matoran, Gavla would have controlled the Element of Light. However, being a Matoran, she did not have this ability to the extent that a Toa of Light would. However, after being exposed to the energies of the Universe Core for most of her life, Gavla was able to use a miniscule amount of Light Energy. This involved changing her color scheme and being able to channel bolts of Light through her Light Blades while in Karda-Nui.
Gavla wore a KanohiAvsa after her mutation into a Shadow Matoran. However, it is unlikely this was her main Kanohi as it would be unlikely that an Av-Matoran would have worn an Immoral Kanohi.
"He looked back to see a sight that would haunt him all the rest of his days. It was Gavla ... and yet at the same time, it wasn't. She had changed in horrible ways. Her feet had sprouted claws, and wings had emerged from her shoulders. Her blades had transformed into talons that were fused to her hands ... no Av-Matoran could change shape like that."
— Tanma, BIONICLE: Legneds 9: Shadows in the Sky
Gavla was released in 2008 with a set number of 8948.