Space Marines - Primaris Gene-Seed and Organs: Though they now stand a step above their Firstborn Astartes brethren, all Primaris Space Marines were still created using the original gene-seed of their primarchs, like all other members of the Adeptus Astartes.Some voices within the Imperium now worry how this new type of transhuman warrior will react to the many genetic quirks and flaws found in the gene-seed of some of the more unusual Chapters, particularly given the long history of fiascoes that have resulted from attempts to alter the Emperor's original work.In the pursuit of his attempt to improve upon the original Space Marine template, Archmagos Belisarius Cawl collected samples of the genomes of all twenty of the original primarchs, including those deemed Lost or Traitors, though Roboute Guilliman made clear to his overeager servant that Primaris Marines were to be created only from the lines of those of his brothers who led the nine Loyalist Space Marine Legions.It is known that in addition to the general advancements in their gene-seed, Primaris Space Marines possess three additional gene-seed implant organs compared to their Firstborn brethren and that their gene-seed is far more genetically stable than that of their forerunners.Primaris Space Marine gene-seed has only a .001% chance of genetic deviancy from the original baseline with the passage of each generation, which makes it nearly immune to the severe genetic instability suffered by Chapters such as the Blood Angels and Space Wolves over the course of their existence.Nearly every Firstborn Space Marine created since the First Founding possesses nineteen specialised organs derived from this gene-seed.The Primaris Marines, however, are implanted with a further three additional organs. It was the Sangprimus Portum, a device containing potent genetic material harvested from the primarchs, that allowed for this breakthrough.Entrusted to Cawl by Guilliman shortly after the Second Founding in the early 31st Millennium, this device resulted in a new breed of Adeptus Astartes that were deployed en masse in the Ultima Founding of ca. 999.M41.Due to Cawl's interpretation of his orders and the millennia-spanning labour of his task -- during which Guilliman was injured and suspended in stasis -- the secrets of these new Primaris organs were not released until late in the 41st Millennium.The Primaris Marines possess all of the nineteen gene-seed implant organs that have been gifted to their Firstborn Astartes brothers, as well as three more that only they possess, for a total of twenty-two.These new gifts of Belisarius Cawl's genius further enhance their transhuman status and ability to bring the Emperor's justice to a galaxy shrouded in darkness and despair. These additional implanted organs include:Sinew Coils (The Steel Within) - The Primaris Space Marine's sinews are reinforced with durametallic coil-cables that can contract with incredible force, magnifying his strength as well as giving his body another layer of defence. A Primaris Space Marine can crush a man's skull in his hand, break Flak Armour to flinders, or even bite through a metal cable should the need arise.Magnificat (The Amplifier) - A small, thumbnail-sized lobe that is inserted into the brain's cortex. The Magnificat secretes hormones that increase the body's growth functions whilst also intensifying the function of its other transhuman implants, especially those of the Biscopea and the Ossmodula. In truth, the Magnificat is but half of the true, dual-valve Immortis Gland (the so-called "God-Maker") that the Emperor created for His primarchs. However, Archmagos Cawl could only find materials and genetic blueprints to build the Dextrophic Lobe (the right half of the Immortis Gland), while plans for the Sintarius (the left half) that would complete the original super-organ had been wholly eradicated from Imperial records of the Primarch Project. Whether this was done by the Emperor's own hand or by some nefarious source, Cawl could not tell.Belisarian Furnace (The Revitaliser) - This is a dormant organ that connects to both Astartes hearts. In times of extreme stress, or should the warrior's body undergo violent, damaging trauma, it expels great blurts of self-synthesized chemicals -- a hyper-cocktail that simulates the biological action of combat stimms while also aiding in the rapid regrowth of tissue, bone and muscle. The gland then falls dormant again, and takes some time to metabolically build itself up once more for the next usage.The Primaris implants are normally introduced between the implantation of the Biscopea and the Haemastamen, steps 3 and 4 above. These procedures are known as the "Primaris Alpha" and "Primaris Beta" phases of the gene-seed organ implantation process. Both phases can be introduced simultaneously.