Space Marines - Power Armour: Possibly the most prominent feature of the Space Marines is their power armour, which is a synthesis of many technologies that pre-date even the Age of Strife, stretching back into the Dark Age of Technology.The suit is comprised of multiple custom-crafted ceramite plates with armoured fiber bundles and servos that replicate the wearer's movements and enhances a Space Marine's already superhuman strength, as well as allowing them to easily withstand brutal attacks that would rip a normal Human apart.The armour itself can also act as a self-containing environment for the suit's owner, protecting the Space Marine from multiple hostile surroundings, including the dark vacuum of deep space and the most toxic planetary environments that the universe can provide.The armour interacts with the Space Marine's nervous system through the Black Carapace, a subcutaneous membrane grown beneath the skin following gene-seed implantation that allows the Astartes' internal organs and nervous system to interface directly with the suit of power armour, so that the armour in essence becomes literally an extension of the wearer's body.There are multiple marks of power armour with significantly differing appearances. Some suits were created for particular tasks – Mark III Iron Pattern armour, for example, was created for boarding actions and is thus more heavily armoured to the fore than the rear -- while others bespeak the bleak necessities of the period of Imperial history in which they were fashioned.The most iconic of this latter type is the heavily studded Mark V Heresy armour, whose entire design is based aroundthe need to rapidly outfit Loyalist Legionaries during the fraught and uncertain days of the Horus Heresy.Some marks of power armour are especially significant to particular Chapters; the Raven Guard, for example,prize the sleek and aerodynamic Mark VI Corvus Pattern armour highly.For thousands of standard years, the iconic Mark VII Aquila Pattern armour was the best known and most ubiquitous design of power armour, but since the Ultima Founding the versatile Mark X armour of the Primaris Space Marines has seen ever more widespread use.However, it was not uncommon for parts of older power armour patterns to be used to replace damaged areas of a Mark VII suit as this saved precious resources.An example of this type of retrofitting was that some Astartes are known to have rivets on certain parts of their power armour. These pieces are actually derived from the ancient Mark II Crusade Pattern armour that dates back to the time of the Great Crusade over ten standard millenia ago.These patched suits of power armour protect their wearers just as well as their updated counterparts since the only real change in power armour patterns over the last 10,000 Terran years have been to the armour's myriad auxiliary systems.What few know is that each Space Marine's suit of power armour is so specific to its wearer that it cannot be worn by 2 different Space Marines without alterations.So precious is his ancient suit of armour that each Space Marine swears solemn oaths to honour and maintain its individual Machine Spirit and the memories of all the honoured Astartes who have worn that particulalr suit over the generations.The introduction of the Primaris Space Marines also brought with it the development of the new suit of more advanced power armour, the Mark X.Unlike its predecessors, the Mark X is intended to be a modular design, more versatile than prior marks and drawing upon the most advanced patterns of the past, particularly the Mark IV Maximus and Mark VIII Errant Patterns.Mark X power armour does not have a single appellation like earlier variants of Astartes battle-plate (such as Mark VII Aquila armour).Instead, different variants of the same mark are worn depending on the Primaris Space Marines' combat role.Regardless of its pattern, Mark X armour is designed to serve as a core exoskeleton that can attach to a special undersuit worn by each Primaris Marine, enabling it to be fitted in different configurations according to need.Intercessor Squads, for example, wear Mark X Tacticus armour. Inceptors, however, wear the Jump Pack-capable Mark X Gravis variant.A third variant is Mark X Phobos armour. This suit's lighter-weight ceramite and streamlined design allow for greater mobility, and its servo-motors are engineered to be completely silent. This variant serves those Primaris Astartes who take on the role of Reivers and Vanguard Space Marines.These Astartes are ruthless killers, trained in covert operations who operate behind enemy lines as saboteurs, assassins and infiltrators. All who wear this variant depend on stealth and secrecy to accomplish their missions.Power armour is maintained by skilled artificers, the most skilled of which are highly celebrated. Examples of their work, and of more ancient armour plating, are preserved with an almost religious fervour, for they carry both the history of the Chapter and the triumphs of those who have worn them.Such pieces are lovingly preserved and engraved, worn across the centuries by high-ranking champions as relic battle-plate.