The Stormsword is an Astra Militarum super-heavy tank that is the result of an ad hoc on-site conversion of a destroyed Shadowsword tank. The Shadowsword's original Volcano Cannon and all of its internal components have been replaced with a massive Hellhammer Siege Cannon, dubbed the "Stormsword Siege Cannon" when deployed on this tank, and an internal storage facility for its giant shells.
The Stormsword has proven to be very reliable in urban combat and is well equipped for close combat and against garrisoned infantry. The Stormsword fills the role of a super-heavy melee tank, while the Shadowsword fills the long-range role, the Stormblade fills the medium-range role, and the Baneblade fills the "all-round" role, capable of fighting equally well in close, medium, and long-range combat.
Eye of Judgment, Assault Sword of the Cadian 8th Super Heavy Armored Regiment.
Like all variants of the Baneblade, the Stormsword arose as a solution to a specific tactical need, in this case the Empire's need for a super-heavy tank suitable for urban combat. The first storm sword was not specifically designed as such by the Techpriests of Mars. During a long and bitter struggle for Coldarkh Hive on a forgotten urbanized world, the Enginseers recover a damaged Shadow Sword, remove the inoperable Vulcan Cannon, and install a Hellhammer Siege Cannon in its place. The resulting vehicle was dubbed the "Stormsword" by its crew, and both the design and the name stuck when Imperial commanders realized the effectiveness of a weapon the Engineers had cobbled together. Since the resounding success of this battle, storm swords have continued to be crafted and used as urban siege engines.
Although the more dogmatic Tech-Priests disapprove of such field conversions, believing them to be an affront to the Machine Spirits and the Omnissiah, the more pragmatic among them judge a design's worth by its results, and accordingly have standardized and started producing Stormswords from scratch their forge worlds.
On the battlefield, the Stormsword is only used in the theaters where view and range drop to almost nothing, typically during city or jungle campaigns. The Storm Sword's colossal mass allows it to plow through most obstacles unscathed, while its massive Hellhammer siege cannon can obliterate any fortification with a direct hit, and its secondary armament of dual-linked heavy bolters and heavy flamethrowers allows it to break out and fire down any enemy infantry with ease.
In the chaos of urban combat, where range is often measured in meters and progress is made in the form of individual buildings captured or destroyed, neither the relatively short range of its armament nor its low speed and maneuverability prevent the Stormsword from wreaking fiery havoc enemies of mankind. When attacking a city, the Stormsword leads the charge, blasting every fortified base to rubble, covering the advancing infantry with its sub-weapons and motivating them with its sheer presence. Of all the close support tanks in the human empire's arsenal, the Storm Sword is the most brutal.
For all its efficiency, the Stormsword suffers from a few drawbacks: its size and bulk are as often a curse as a blessing, as there will invariably be instances where the Stormsword is too big to fit in, yet unable to clear obstacles to plow through. As with all Shadowsword variants, the Stormsword's fixed main gun requires the tank to be aimed body-on-target, and the Stormsword's crew must be specially trained to spot and avoid pitfalls that get their massive tank stuck or a potentially disastrous trail would lose results.
The Hellhammer Siege Cannon has a very poor rate of fire and is actually a bit too big for the Baneblade chassis, allowing a Storm Sword to only carry 20 shots, 21 if the crew risked summoning the main gun. The Stormsword also lacks anti-tank armament, as only its main gun can destroy enemy tanks, and as such the tank requires support from anti-tank infantry units when advancing. Finally, the Stormsword is all but useless outside of urban combat due to the short range and poor rate of fire of its main gun combined with the poor top speed and maneuverability of all Baneblade variants.