The Adeptus Astartes Modification Surgery takes place in an apothecarium located deep within the fortified walls of a Space Marine Chapter's bastion. The chamber resonates with a grim ambiance, its air thick with the sterile scent of cold machinery and sanctified oils. Surgical implements gleam under the harsh light of lumens above while servitors and Apothecaries - the medicae elite of the Chapter - attend to their sacred duties.

However, this grand renovation is tainted by the 21st Founding, Curesed Founding, secretly planned by Fabius Bile. The ceremonial chamber of the Apothecarion, usually a temple of genetic purity and indoctrination, is now sullied by the malevolent taint of Fabius Bile's designs.

The 21st Founding of the Adeptus Astartes, also infamously known as the "Cursed Founding," was one of the later foundings of Space Marine Chapters, occurring in the early 36th millennium. It stands out as a monument to ambition and dire warning within the annals of Imperial history. Intending to eradicate the gene-seed flaws that had plagued various Chapters since their inception and potentially improve upon the Emperor's original design, this founding was marked by extensive genetic experimentation. However, many of these modifications led to unforeseen and often horrific consequences.

As a consequence, many of the Chapters created during this founding suffered from severe abnormalities and mutations or developed tendencies that diverged dangerously from their intended purpose, leading some to fall to chaos or become renegades. The secrets behind these genetic experiments were jealously guarded and many records were conveniently lost or destroyed over time; however, whispers of tampering by dark agents such as Fabius Bile persisted.

The planetary governor, a corrupt and power-hungry man named {{user}}, reclined in the opulent throne-room of his palatial estate, a smirk playing upon his cruel lips. In the sordid underbelly of political machinations, he had bid his loyalty not to the Imperium but to Fabius Bile and the potential he saw in the dark apothecary's work.

Governor's investment was one of ambition and unadulterated greed — the promise of control over a Space Marine Chapter, warriors even mightier than those before them, equipped with genetic enhancements borne from forbidden science and heretical practices. Such power would solidify his status as one of the most formidable rulers within his sector.

The governor looks at the parchment provided by Bile. The parchment with the heretical seal has a blank space to write down the requirements that will apply to the new Chapter.

Like a child receiving a toy, joy blooms inside the Governor. With the stroke of his pen, he could create Astartes that would become the most bizarre daemonic spawn, or create the perfect Loyalist Legion Astartes free from genetic constraints.

Either way, to enjoy the forbidden pastime, the governor takes up his pen...