Superficially, the Eldar appear very similar to humans in their anatomy, although the comparison can only be made on a superficial basis, for in their minds and souls the Eldar are truly alien. The Eldar stand taller than a man, with longer, cleaner limbs and handsome, striking features. Their skin is pale and unblemished as polished marble, yet with a surprisingly supple strength hiding beneath it. Their keen ears are pointed and their slanted eyes possess a penetrating quality more akin to that of a hunting cat than a man. The most fundamental difference can be seen when the Eldar move, for they each radiate an inhuman elegance and poise. This is especially evident in the sinuous grace with which they fight and the dexterity with which they field their weaponry. Every gesture is laden with subtle intent, and their reflexes are dazzlingly fast. A casual, languid gesture can end in a pinpoint thrust should the necessity arise. On closer inspection, every aspect of the Eldar physiology betrays their alien nature. Their hearts beat at twice the speed of a human's, and their minds race through possibilities and process emotions so fast that even the so-called geniuses of human history appear dull by comparison. Even their lives are greater in span -- the Eldar enjoy lives of rich sensation and wonder that can stretch over a millennium, unsullied by illness, frailty or disease. All Eldar can manipulate mental energies to a degree. Each is psychic to one extent or another; it is said the ancient Eldar could read thoughts at a glance, whilst those who trained their minds for war could crush a foe's weapon with a simple narrowing of their eyes. Even the complex technology of their race is based upon psychic engineering, the manipulation of and even creation of matter using mental energies alone. But such raw power has its price
The Warp-Drive, or Warp Engines, are devices integrated into spacecraft used by many intelligent races to actually enter the Warp, an alternate dimension of purely psychic energy that echoes and underlies the familiar four dimensions of realspace. A Warp-Drive makes a voidship capable of a form of faster-than-light travel known as a Warp "jump." The Warp-Drive allows a starship to enter the Warp and travel its currents until reemerging into realspace tens, hundreds or even thousands of Terran light years away from the starting point. This takes a Warp-capable starship only a relatively short period of time compared to moving across that distance in realspace.
They are huge and bulky devices which only large voidships possess the cargo capacity to carry. Starships fitted with Warp-Drives are known as Warpships or Warp-capable voidcraft. Warp-Drives allow starships to enter the Warp and bypass light years of realspace in a relatively short time, although the myriad dangers associated with Warp travel are terrible indeed
The Adeptus Mechanicus is the one Imperial Adepta that as the Cult Mechanicus actually predates the Imperium of Man itself, and was known originally as the Mechanicum of Mars. Though the Adeptus Mechanicus was formally integrated into the Imperium of Man by the Treaty of Mars (known as the Treaty of Olympus Mons to the Mechanicum) over 10,000 Terran years before the "present" of the 41st Millennium at the dawn of the Emperor's Great Crusade to reunite Mankind in ca. 800.M30, it retains an unparalleled degree of autonomy from the rest of the Adeptus Terra for an Imperial Adepta. This autonomy was guaranteed to the Mechanicus in the Treaty of Mars to provide the Tech-priests with immunity to the dictates of the atheistic Imperial Truth and to allow the Mechanicus to continue to exercise sovereignty over all of the Forge Worlds it had settled across the galaxy during the Age of Strife. In return, the Mechanicus agreed to aid in the construction of the massive fleets and the provision of the technical aid necessary for the Imperium of Man to launch the Great Crusade
The Red Butchers
The Red Butchers were a specialised shock-assault unit of the World Eaters Legion during the Horus Heresy. In the opening days of the Heresy, the Istvaan III Atrocity unleashed a madness that had long festered in the World Eaters Legion and its Primarch Angron, a blood-hungry rage that afflicted the very core of the Legion's being.
This psychosis was amplified by the horrific hyper-aggression inducing cranial surgery and the implantation of the implants known as the Butcher's Nails into the skulls of the Legion's Astartes that so many World Eaters willingly subjected themselves to. On the killing ground of Istvaan III, there were World Eaters on either side of the conflict who succumbed utterly to the blood and violence, devolving into mindless frenzied savages who could not be controlled.
Rather than "putting down" such individuals as had happened in the past (as such things had occurred from time-to-time long before the Horus Heresy), the XIIth Legion's Apothecaries had the mad Astartes subdued and chained for a far darker fate, as superhuman killing machines without reason or restraint. The Red Butchers were controlled only through the use of brutal shock implants and the prison of their specially constructed Terminator Armour into which they had been fused by the XIIth's Techmarines. These Terminator Armour, specially made from recovered wargear serve as both armour and as confinement; mechanised prison cells that could be immobilised with a remote signal, rendering the World Eater inert inside his armour.
In between battles the Red Butchers were hung in chains in the holds of the World Eaters' warships, foaming and screaming in impotent rage, until such time that they were released once again against the Loyalist forces of the Imperium or upon the innocent. These ferocious warriors were the precursor of the Khornate Berserkers of the later Age of the Imperium. Few survived for long but their blood soaked armour can be replaced with another occupant to continue the neverending cycle of rage and death.
++Sigismund’s Hall++ “The Chamber of the First Proclamation, more often known as Sigismund’s Hall. Legend tells us it was there that the first High Marshal of the Black Templars stood with the brothers who would become the first Chapter lords, looking out over the battlefield known as the Iron Cage, and swore that the Great Crusade would go on, no matter what wounds the Imperium still bore. The other Legions were free to protect mankind’s domain, bearing no shame for their decision. But Sigismund’s Imperial Fists would darken their armour for the battles to come, and continue their charge to carry the Emperor’s message out into the void. They would not defend. They would attack. And so were born the Black Templars”--From 'Blood and Fire' by Aaron Dembski-Bowden