Virus Cannon

''The Virus Cannons were a series of twenty-four cannons built by Makuta Burtok. They were later rigged to explode and damaged Burtok's fortress.''

History
The cannons were built by Burtok with the intent of using an organic matter-eating virus to annihilate all the life on Crystal Island except himself. To not waste his minions, he absorbed them into his essence and gained power from this.

The Avenging Alliance was captured, but broke out, and they found the cannons being maintenanced by little robotic arms inside the cannons and the self-sustained force field that protected them. The Alliance tried to down the field by knocking out the power, but it took the help of Bultrox's sword to down the field. Lohrua and Suntrah rigged the cannons to explode if fired, and, when they escaped, fired they were, and explode they did, taking out the outer wall of Burtok's fortress.

Function
The cannons used compressed fuel to propel Tridax pods full of virus to the island. The fuel is lit under pressure, and this propels the sphere out of the cannon over the island.

Trivia

 * The cannons exploded with a lot of force, but it was really the fire and shrapnel (they were made of protosteel) combined that felled a lot of the fortress.