A Londo Bell mobile suit intended as another attempt to mass-produce the MSZ-006 Zeta Gundam, after the RGZ-91 Re-GZ series was deemed a failure based on an evaluation of its overall combat performance and production costs. It uses the basic frame of the RGM-89 Jegan and has a transformation system similar to the MSA-005 Methuss and the MSZ-008 ZII instead of the Back Weapons System (BWS). It is currently unknown if the ReZel is capable of atmospheric flight or orbital re-entry. The ReZel has an newly installed OS for ease of operation and control. The OS supports a limiter that comes into operation to lower the marginal performance of the ReZel so that the MS can be handled without difficulty by rookie pilots. However, experienced pilots can deactivate the OS to execute complex maneuvers.
The Commander Type units are specialized machines with re-adjusted performance specifications for ace pilots, and are primarily operated by unit commanders. There are only minor cosmetic differences between the normal ReZEL and theCommander Type, most notable of which is a set of wing binders mounted on the back of the latter inspired by theMSN-00100 Hyaku Shiki. The normal ReZEL has distinct purple lights on its frame where the Commander’s unit has green lights instead.There are some addition optional equipment and weapon shown in the Unicorn Gundam comic
In the events of Mobile Suit Gundam Unicorn, ReZEL units deployed to engage in combat with the Sleeves in the space colony Industrial 7. During the battle inside the space colony Industrial 7, several ReZELs and Jegans were deployed by the Nahel Argama and other Federation forces to combat the NZ-666 Kshatriya in the colony Industrial 7. Despite having superior numbers, the combined Jegan and ReZEL mobile suits were defeated and destroyed by the Kshatriya. One standard type ReZEL unit was piloted by Londo Bell‘s Riddhe Marcenas.
Three more ReZEL units along with a RGM-89S Stark Jegan were deployed by the Nahel Argama during the Full Frontal‘s attack on the Nahel Argama. Two of the three ReZEL units were destroyed by the MSN-06S Sinanju until the sudden appearance of the RX-0 Unicorn Gundam.