When the firing impulse is sustained, each weapon can fire a constant stream of nuclear fusion-based Melta energy that blazes from the muzzle of the weapons like a blade of pure light.
Fusion Blades are a rare T'au Battlesuit weapons system that was created at the request of the third bearer of the title of Commander Brightsword. Fusion Blades are potent close combat weapons that are easily able to vaporise infantry and carve through tanks.
Indeed, the seventh Commander Brightsword used his Fusion Blades to extreme effectiveness against even the giant bio-monsters of the Tyranids.
However, Fusion Blades consume an incredible amount of energy to wield, and are prone to shorting out in the midst of battle. Fusion Blades are a T'au weapons technology employed exclusively by the Farsight Enclaves.
- Farsight Enclaves - A Codex: Tau Empire Supplement (6th Edition) (Digital Edition), pp. 218, 307
- Rogue Trader: Tau Character Guide (RPG), pg. 38