|“||Lerahk is poison, and I mean it!||„|
|~ Takua referring to Lerahk|
Lerahk was released by the Makuta along with Panrahk and Guurahk to stop the approach of the seventh Toa. He and his fellow Rahkshi attacked Ta-Koro in search of the Kanohi Avohkii (the Mask of Light). Lerahk was hit on the head by Turaga Vakama until Tahu decides to face him. Lerahk scratched Tahu's mask infecting it with poison. Lerahk, Gurrahk, and Panrahk then escaped Ta-Koro by using their staffs to fly.
Lerahk, Gurrahk, and Panrahk later tried to apprehend Takua and Jaller on Ko-Koro. However, they were intercepted by Kopaka, who froze them inside a nearby lake.
Some time later, Lerahk, Gurrahk, and Panrahk managed to break out of the frozen lake and join Turahk, Vorahk, and Kurahk. The six Rahkshi assembled at Kini-Nui, where they gave chase to Takua and Jaller. The six Toa Nuva arrived and were able to defeat the Rahkshi.
Lerahk's body was later used along with the other Rahkshi's to create the Ussanui.