The Shoopdahk's purpose was to fight Teridax and his armies who recently took over the BIONICLE world. We have seen a prototype as well as a working squad of Shoopdakh. The Prototype was based on a Vahki Nuurahk, while the working ones were based on Rorzakh. Interestingly, the Shoopdakh are capable of speaking unlike regular Vahki who talk in noises unknown to most beings.
The Prototype Shoopdakh is capable of firing its Kanoka disk saying "I'MMA FIRIN' MAH KANOKAH!!!" and then proceeded to blast a powerful Shoop da Whoop laser, though with a delay. The official squad is capable of firing a devastating blast along with Kanoka in their sheer velocity.