The RX-160S Byarlant Custom is the first of two Bylarant Customs developed at Torrington Base by upgrading surviving units of the disgraced Titans' RX-160 Byarlant. The project's aim is to improve the Byarlant's unique independent atmospheric flight capabilities. To achieve this, the RX-160S had its thrusters enhanced, and a pair of back-mounted propellant tank/thruster units added, increasing its mobility and extending its independent atmospheric flight time. Its head sensor has been changed from the original's mono-eye sensor to an EFF standard visor-type sensor that incorporated twin eye camera, and was specifically requested by Federation Forces HQ before they would approve the project.
Other notable changes included significantly improved main weapons, and revised limbs featuring parts from other Titan's mobile suits. Its arms were modified with parts from the RX-110 Gabthley's claw arms, while its feet's new heels originated from the NRX-055 Baund Doc. As a result, development staff referred to this project as a Kirin or Chimera of Titans mobile suits. Although the RX-160S did not incorporate the latest technology, it still achieved improvement in overall performance over the original. As the first Bylarant Custom unit, the RX-160S served as a technology testbed to validate the various modifications, with the second unit incorporating further improvements to create the perfected version.
After the Gryps War ended in early U.C.0088, the Earth Federation Forces wanted to distance themselves from the Titans and their atrocities, and so decommissioned the mobile suits developed by the latter. As a result, surviving units of the RX-160 Byarlant were put into storage. Sometime later, a development plan to modify the surviving units to achieve better independent atmospheric flight capabilities, the unique characteristic of the Byarlant, was submitted and eventually approved.