Battle of Maethrillian II

It was the Battle of Maethrillian II that was the toughest conflict that the chapter had faced. The chapter was sent to investigate distress calls from the world of Maethrillian II, which had been previously classified as a dead-world with a particularly violent atmosphere. Unknown at that point, the planet Maethrillian II was home to an artefact of unknown age; theorised to have been created by either the Necrons. It appears capable of ripping nearby ships out of the Immaterium and into realspace. It's unknown whether this is the true purpose of the device, or whether this is a side effect of it's activation.

While travelling to this region, the Storm Marcher's fleet was violently ripped out of the Warp. The majority of the fleet's vessels including the chapter's flagship Strike-Cruiser crashed onto the planet Maethrillian II. The chapter's other two other Strike-Cruisers managed to stay in orbit. Even with their specialised tactical equipment the chapter had difficulties communicating through the vicious weather. The world was desolate with waves of violent storms and towering walls of dust that regularly turned daytime into night. Chapter Master Avirus Corbulo gathered together the remainder of his 1st, 2nd and 3rd Companies from his crashed Battle-Barge.

 In orbit, the two remaining Storm Marcher Strike-Cruisers attempted to locate the Chapter Master and the rest of their forces, but a damaged Tzeentch Silver Tower emerged from around the other side of the planet having been previously ripped from the Immaterium in the as well. The cruisers engaged with the Daemon Engine.

On rare moments that the surface weather parted, a black spire became visible to the east, rising high above the mountain range. The tower appeared active, with a green glow emanating from within. Seeing this as the cause of their crash, Avirus took his 1st and 2nd Companies, leaving the 3rd Company to protect the downed Strike-Cruiser, and began a mechanised advance towards the obelisk. Chapter Master Corbulo considered leaving an entire company was overkill, but considering that repairing the Battle-Barge would be their only way off of the planet, he felt it a necessary precaution. He was quickly proved right.

The Storm Marcher's were not alone. After travelling across the surface of the barren planet, Avirus and his marines came across pockets of xenos survivors who had also crashed on the planet decades ago, and were now marooned. Avirus knew that there was now a real risk that other xenos would have seen the Storm Marchers crash, and would see their ships as their only way off of the planet. However, he had to keep pushing towards the infernal machine that was the cause of the crash. If the machine had truly been responsible for ripping his and other ships out of the Immaterium, then it could surely provide a gateway for the forces of Chaos, if it hadn't already.

The wreckage of an Ork ship had been cobbled into makeshift shelters, and the chapter had no choice but to fight their way through the horde. Ork and Drukhari raiding parties began attacking the chapter's downed Strike-Cruiser in hopes of using it for parts, and the 3rd Company fought hard to hold them off with limited visibility.

 The hover engines of the Impulsor and Repulsors proved troublesome in intense wind-speeds of the planet, and so Avirus and his troops of Marines, Aggressors and the six Primaris-Centurions of the 1st Company held out against the storm on foot. When they reached the machine, metal skeletons began rising out of the sands as if triggered to protect the structure. The Necrons were completely unaffected by the planet's violent weather, and so the Storm Marchers fought hard to get inside the machine and destroy it. The Chapter Master and his forces managed to deactivate the Necron Pylon, and the Strike-Cruisers were able to destroy the already damaged Silver Tower.