With the decoding of Star League secrets, one of the first steps taken by House Davion was to begin making plans to improve upon the already-fearsome Marauder. This eagerness backfired when the Draconis Combine captured the Marauder factory on Quentin during the War of 3039. The Combine built the MAD-5D there for decades, until the Jihad began to heat up. Then, with new technologies coming out, the Dragon upgraded the design and sent it out to do battle for the Combine. Unfortunately, Quentin fell and as the Jihad wore on so did most of the new MAD-9Ks. After Tikonov captured Quentin, they repaired the factories and put the 9K back into production.

         The MAD-9K design employs double heat sinks to handle the increased heat generation of a host of new weapons. The extra-light engine saves enough weight for an impressive fourteen tons of armor, giving it far more armor than older Marauders. This model also has jump jets, like the older 5D, further endearing the design to its pilots. The entirely new weapons array consists of three Dragon's Fury light PPCs, one in each arm and one attached to the underside of the Dragon's Wrath Heavy PPC that can do as much damage as a Clan PPC. It is the amazing array of eight Intek medium lasers though that make it a veritable whirlwind in close-range combat that few enemies look forward to approaching. A Matabushi Citizen C3 Slave system also links the 9K into a C3 network, making them even more deadly than normal when working with similarily-equipped units.

         Mainly used by the Tikonov Republican Guards, the MAD-9K is often used to support Cataphract lances as a bodyguard 'Mech, keeping enemy lighter units from closing the range. Few enemies wish to brave the Marauder's array of medium lasers, making them a very good bodyguard. When deployed without Cataphracts, the 9Ks usually anchor a main battleline, advancing on the enemy and forcing them to decide whether they will retreat or die. There is rarely a third option for them.