After being stolen by ZAFT and damaged in battle with the GAT-X105+AQM/E-X01 Aile Strike Gundam, the suit is upgraded with the Assault Shroud. The Assault Shroud is a set of ejectable armor mounted on the Duel’s body to enhance overall combat performance. It adds a "Shiva" 115mm railgun to the right shoulder and a 220mm 5-barrel missile pod to the left shoulder for additional firepower, as well as various leg and backpack-mounted thrusters for better mobility.
A ZAFT manufactured add-on, built for the Duel after it was damaged in combat. It is based on similar equipment used by the ZGMF-1017AS GINN Assault Type and the ZGMF-515AS CGUE Assault. The Assault Shroud increases the Duel's battle effectiveness by granting it extra armor and new weapons like the "Shiva" Railgun and a Missile Pod. It also contains additional vernier thrusters to enhance Duel's mobility in space and offset some of the added weight. However, the latter is effective only in space and the extra bulk still hinders the Duel's movement when under gravity. Additionally, the Duel's Phase Shift Armor does not extend to the Assault Shroud.