Asuryani - Anatomy and Physiology: Superficially, the Aeldari 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 Aeldari are truly alien. The Aeldari stand taller than a Human male, with longer, cleaner limbs and handsome, striking features to Human eyes.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 Aeldari 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 Aeldari 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 Craftworld Aeldari enjoy lives of rich sensation and wonder that can stretch over a thousand Terran years, unsullied by illness, frailty or disease, unless they die by violence or accident.All Aeldari can manipulate mental energies to a degree. Each is psychic to one extent or another; it is said the ancient Aeldari 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 same neurological mechanisms that grant the Aeldari mind such power also inclines it far more towards extremes than that of a Human. To an Aeldari, all of life's experiences are available on a far grander scale: the individual rewards of study, the exhilaration of battle, and every imaginable pleasure or sensation in-between.An Aeldari will at some point climb the most noble peaks of accomplishment, just as they will plunge into the darkest abyss of doubt. Their capacity to experience emotion enables them to attain transcendent bliss or, in contrast, experience soul-wracking sorrow.This spiritual intensity is writ large throughout their culture, manifesting in sublime works of art and music, but also giving rise to a darkness that threatens to engulf them all. No creature, not even an Aeldari, can taste such rich fruits in an uncontrolled way without consequence; for an Aeldari to yield absolutely to the intensity of their desires would destroy them. Such was the fate of their ancient empire, whose depravities brought about the Fall of the Aeldari race itself.The Aeldari that actively cultivate their psychic potential seem to exhibit a much-extended lifespan even by their standards as well, one proportional to their prowess as a psyker. In this way the leaders and Seers of the Asuryani may live for several thousand standard years.One matter of note is that the Aeldari have sometimes referred to Humans simply as "mammals" typically with a derogatory label in the Aeldari Lexicon like "the Mon-Keigh," implying that for their part, the Aeldari evolved from something else, something more advanced than the primates that are the ancestors of Mankind.However, given the Aeldari's legendary arrogance and fickleness, this may also simply be a way for them to put themselves above the other intelligent races of the galaxy, particularly the Humans who are currently the most dominant intelligent species, much to the Aeldari's disdain.The Aeldari likely see themselves as completely separate from the normal classifications of animal groups. Indeed, they may not even have naturally evolved at all, as they are the genetic creations of the Old Ones, much like the Orks, created to defend the galaxy and the Old Ones' civilisation from the depredations of the Necrons and their C'tan masters during the War in Heaven.