The Sword Calamity represents an evolution of the GAT-X131 Calamity Gundam, shifting from heavy artillery to a design optimized for melee engagements. This adaptation takes inspiration from the armament philosophy of the GAT-X105+AQM/E-X02 Sword Strike Gundam, incorporating a dual-purpose main armament of large anti-ship swords that double as laser cannons. The arsenal is rounded out with beam boomerangs, rocket anchors, and combat knives, diversifying its close-quarters combat capabilities. While it maintains the original Calamity's energy cannon, this weapon has been adjusted to trade firepower for extended use.
To align with its melee orientation, the Sword Calamity underwent modifications to its fire control systems and electronic warfare capabilities. It also preserves the Trans-Phase Armor from its predecessor. Of the three units produced, the first Sword Calamity retains the base color scheme of the original Calamity Gundam on its unchanged sections. This decision was made as the first unit served a dual purpose: not only as a combatant but also as a testbed for further Calamity Gundam variant development under the 'Rebuild 1416 Program.' However, this initiative was eventually abandoned in favor of adopting the GAT-01A1 Dagger for future multi-role mobile suit development by the Earth Alliance.
The Sword Calamity emerged as a melee-focused derivative of the GAT-X131 Calamity Gundam, operated by both Naturals and Combat Coordinators, diverging from the use of Biological CPUs. Concurrent with the original Calamity's timeline, a trio of Sword Calamity units were manufactured. The inaugural unit was primarily for data collection and was subsequently archived. The remaining pair saw action, helmed by Earth Alliance elites Edward Harrelson and Four Socius under Rondo Gina Sahaku's command during the pivotal Third Battle of Victoria, significantly contributing to the Earth Alliance's triumph over ZAFT.
Post-testing, the second and third units were actively deployed. Four Socius, along with his Sword Calamity, were transferred to Orb's Sahaku clan by Muruta Azrael. An attempt on Cagalli Yula Athha's life, under Gina's directive, was foiled by Gai Murakumo in his MBF-P03secondL Gundam Astray Blue Frame Second L.
Harrelson's Sword Calamity engaged in the Second Battle of Jachin Due, where Harrelson decided to turn against the Alliance. Post-conflict, Harrelson defected to the United States of South America. Subsequently, the first unit was reactivated and assigned to Rena Imelia, tasked with pursuing Harrelson. Their confrontation ended with both units damaged and the pilots injured. Kaite Madigan recovered the battered Sword Calamity units for his collection, promising Jess Rabble that Harrelson's unit would be returned upon request.