My custom Chapter for Space Marine 2 w/ added short story lore.
Name: The Black Scythes
Born of the 21st founding.
Successor Chapter of The Imperial Fists. (May in truth be spliced with Iron Warrior gene-seed.)
Chapter Master: Malion Blackhand
Homeworld: Crucible
Fortress Monastery: The Black Forge
Colors: Black, Yellow, and White.
Battle Cry: "Craftsmanship beyond compare, valor beyond measure."
Specialty: The crafting of masterwork weapons, armor, vehicles, vessels, siege works, and fortifications.
Strength: Considered among the best equipped chapters with access to the most advanced wargear.
Weakness: This chapter is known to be very few in number.
Curse: Black Scythe gene-seed is known to be highly volatile, killing all but the strongest supplicants exposed to it. Those that accept Black Scythe gene-seed and survive suffer from mutations including pale or even gray skin, and glowing fiery yellow eyes.
Unique abilities: The Black Scythes are known to be unusually durable with an equally notable stamina to match. They are known to have an usually high tolerance to Chaos Corruption making them both valued allies of and under close observation by The Emperor's Holy Inquisition.
[Disclaimer: Lore has been slightly summarized to make the post more digestible.]
Lore: During M36, amidst the Great Apostasy, The Black Scythes—with a modest flotilla of warships and no home world—faced isolation and skepticism due to their 21st Founding origins. Seeking to prove their worth, they engaged in minor conflicts, eventually responding to a distress signal from a Mechanicus explorator fleet. Chapter Master Malion and his flotilla observed a chaotic battle within the fleet, initially staying back until the Techmarine Rurik Adamalus suggested it was the work of hereteks. This convinced Malion to bring his flotilla to battle against the perceived hereteks.
Facing the certain defeat posed by an Oberon Class Battleship falling under heretek control, Malion took drastic action. The Black Scythes' flagship, Iron Requiem, was rammed into the battleship and its warp drive detonated, causing a massive explosion that shifted the battle's odds enough to secure victory. The remaining forces of the explorator fleet, now significantly reduced, revealed that the fleet had been infiltrated by the Ordo Hereticus which outed their Arch-Magos as heretek sympathizer.
With the hereteks and Inquisition destroyed in the battle, loyalist Magos Volthor Mecharius led the surviving fleet. The Magos was bound for the Gharn System on the eastern fringe of the Ultima Segmentum. His intentions were to uncover the plans of the now dead Arch-Magos. Knowing that the remnants of the explorator fleet could not accomplish this alone, Malion pledged the Black Scythes' support to Mecharius, marking the beginning of a significant alliance and mission for the chapter.
The Black Scythes had followed Magos Volthor Mecharius to the Thramas Exclusion Zone, a hazardous region of space with numerous black holes that disrupted even Warp travel. This area forced all merchant and military traffic to use slower, stable Warp channels leading to the Hive World of Sheol III, creating a strategic bottleneck which consequently enriched Sheol III.
Malion and Mecharius had eventually navigated to the Gharn System, located at the heart of the Exclusion Zone. There, they discovered Crucible, the eighth planet in the system, which featured an extensive chain of orbital shipyards, refineries, and construction facilities encircling its equator. This structure resembled a smaller version of the Iron Ring of Mars.
Upon investigating Crucible, they found it occupied by a small Adeptus Mechanicus force left to maintain the Iron Ring installation. The larger Mechanicus force that had built the ring had departed for another project near the Triplex System. The custodian of the installation, Magos Domanius Xol, revealed that the Iron Ring had been commissioned by the now-deceased Arch-Magos previously outed as a Heretek.
Malion had chosen to investigate the Triplex System construction project, while Magos Mecharius stayed to examine the Iron Ring of Crucible. Brother Rurik Adamalus, being a techmarine and expert on the Machine Cult, was put in charge of half the Black Scythes to protect Mecharius, while the rest accompanied Malion.
While Malion and his forces were away, Mecharius uncovered that Magos Domanius Xol was another heretek sympathizer. Mecharius and Rurik purged Xol and his followers but discovered that they had sent a coded distress signal to the Triplex System, likely summoning hereteks to Crucible. Unable to reach Malion to warn him, Mecharius and Rurik set to prepare for an imminent invasion. Mecharius and Rurik made liberal use of the Iron Ring’s facilities to ready themselves and their men for battle.
Meanwhile, Malion and his forces arrived at the Triplex System’s construction site, only to find a decimated Adeptus Mechanicus fleet and soon faced an ambush by a heretek fleet. To delay the hereteks long enough to escape, Malion sacrificed one of his remaining two battlecruisers. The hereteks did not pursue him to Sheol III due to the formidable defenses stationed there.
Malion suspected that the heretek fleet was heading to Crucible to attack the Mechanicus garrison and his forces. He negotiated with the Imperial forces of Sheol III to assist in securing Crucible at a cost.
On Crucible, the Mechanicus and Black Scythes fortified their defenses with the best wargear and ammunition available. The Iron Ring installation was stocked with advanced blueprints, aiding their preparation for the invasion. When the heretek invasion began, the automated orbital defenses of the Iron Ring initially held off the heretek fleet, inflicting significant damage. However, heretek forces eventually infiltrated and began disabling planetary defenses, allowing more reinforcements to land and assault the Iron Ring’s surface.
The battle was fierce, with hereteks capturing all but the control citadel where Mecharius and Rurik stationed most of their forces. As defeat seemed imminent, Malion arrived in orbit with Sheol III’s Navy and a portion of their Astra Militarum garrison. Despite the intense fleet battle, Malion focused on rescuing his men on Crucible. He led a ground assault with the Astra Militarum, breaking through heretek lines and lifting the siege on the control citadel.
Malion found that Magos Mecharius had survived, but Rurik Adamalus had sacrificed his life to save the Magos. The hereteks were driven from Crucible just as the Ordo Hereticus arrived. The Inquisition confirmed that the Black Scythes had acted correctly and that Mecharius’s Mechanicus forces had remained loyal to the Imperium. An Inquisition outpost was established on Crucible to monitor the system and later the Black Scythes.
The Adeptus Mechanicus fully staffed the Iron Ring, promoted Magos Mecharius to Arch-Magos, and granted him dominion over the Iron Ring of Crucible. The Black Scythes were given Crucible itself as their homeworld in gratitude. The Iron Ring was later used to forge a fortress monastery, which the Black Scythes moved into orbit around Sheol III. They pledged to protect Sheol III in appreciation for its aid in defending Crucible from the heretek invasion.
The Black Scythes have remained ever more, the grim guardians of Crucible, the staunch allies to the Adpetus Mechanicus, and the loyal servants of the Imperium.