Rermus Campaign

The Rermus Campaign was an Imperial xenocidal campaign conducted by the 501st Cordanian MIR, as well as other supporting Astra Militarum regiments, Adeptus Mechanicus forces, an element of Squats and the Ordo Xenos itself, to purge the vital important Imperial world of Rermus of an unknown and unrecorded xenos threat.

History
On an agri/research planet of Rermus, an unknown enemy appeared on the planet from under the surface of the planet and dig their way through to the civilian settlements and PDF base across the planet. The call for aid has been sent into Terra. Segmentum Command has sent in the 501st Cordanian MIR, 302nd Cadian Shock Troops Regiment, and small elements of the Kasrkin Stormtroopers. They also have to accompany with Inquisitor Agrippa from the Ordo Xenos to investigate the planet and the status of the research stations. When they got there, most of the population was killed and the survivors were sent to the last PDF/Research stations that were on the planet. Which was using an experimental psychic field which masks their location from the unknown xenos race? So they set up their forward operating base in the research station. They have also set up a command center in the main administrative building of the station. But as for most of the base, Astra Militarum, and the civilian population was not allowed enter most of the base as they are under the rule of the Inquisition. Only members were allowed to roam free across the station, but any found getting close to the main entrances of the main research builds, was prosecuted and was not even seen again.

As for the unknown xenos enemy, during the regiment's first engagement, they brought back the remains to Inquisitor Agrippa to study. They also have to give her accounts about the tactics and behavior of the xenos race. They gave their accounts that they do have the intelligence to use most of the basic weapons the Imperial Guard. But the majority of them will simply rush at the targets with their massive numbers to try overrun the squads. Using makeshift weapons such as blades or even using their own sharp rodent-like teeth. They even had an encounter with larger versions of the xenos race, which have been theorized that this is some type of mutation or some type of warp influence being used to create these abominations.

Over the past few months, they have been fighting the hostile xenos race to regain lost PDF bases from the vile xenos. They soon got additional help from the 182nd, the Scotia Warriors. As they used their power shields units and melee skills to fight the Xenos at their own game. But thanks to the Squat's forge masters and the Mechanicus elements from Manis. They came up with an idea to finally end the xenos threat. They used specialized missiles which will dig down the mapped tunnel systems and donate their promethium payloads to fill the tunnels with fire. This took some time for them to get most of the tunnels mapped out then they unleash specialized missiles across the planet which caused earthquakes across the planet. But this killed 90% of the xenos race. But the rest was ruthlessly hunted down and purged by Imperial Forces... down to the last. But it is still unknown which xenos race they were or how they got onto the planet as well as how long they had already been there when humans first settled the planet. Most of this knowledge and answers to these particular questions are locked away under the orders of the Inquisition.