Illiyan Nastase

Rawr! I hate this!

Some older fluff mentions that Eldar and Humans both were created by the Old Ones, and therefore should be able to give birth to Eldar-Human hybrids. This, of course, is mad old fluff that can't be trusted to function anymore, and you can be sure that your friends at the Inqusition will tell you that mating with an Eldar will result in corruption, mutations and one hideous baby, before promptly blamming you.

Suffice to say, back in the old Rogue Trader days there were not only Human-Eldar halfbreeds, but some openly found their way into the upper echelons of the Imperium.

Illiyan Nastase was born on Badab towards the end of the Badab War in M41.912 to a human mother and Eldar father. After genetic testing was taken into Imperial Custody and when he was twelve years old was sent to Terra because he was a psyker.

He was then Soul-Bound to the Emperor and worked for the Administratum as an Astropath where he rose in rank to "Secundus Prefect" and held the position of "Consul" for four years where he was an advisor to the Master of the Adeptus Astra Telepathica.

THEN he was attached to the Dark Angels for a further two years.

After which he was promoted to Chief of the Macragge communications link and somehow holds the rank of Chief Librarian within the Ultramarines.

Why this is bullshit

First, Eldar & Human hybrids are extremely unlikely, despite possibly sharing a common ancestor, the two species are probably so far apart that offspring are not viable, especially since Eldar DNA contains considerably more base pairs (which are used to determine amino acid structures) than humans do, and their DNA contains more helices (and therefore more information). Not to mention whether or not they have the same number of chromosomes.

• This does not render human/eldar offspring absolutely impossible (plus Genestealers manage to do it, although through an invasive process) but if it were ever to occur you'd probably get some stunted flesh-freak whose body was completely at war with itself due to incompatible proteins and/or missing genetic information.
• Even if Human/Eldar proteins were compatible, then any offspring would have a phenotype greater than 99.99% Eldar, since the 20 Eldar base pair combinations would already include the 2 base pairs that the human genome (and all life on Earth) has, making the contribution from the human DNA become exponentially tiny and would essentially amount to what would be an inbred Eldar.

Secondly, any such offspring would be considered an abomination under Imperial Law and by the Ecclesiarchy and would be put to death, despite the fact he was born on Badab during the Badab War and was generally ignoring both. Lugft Huron was a political secessionist at that time, and not the raving chaos lunatic that he would later become. So any official sanction of a Human-Eldar hybrid would be extremely unlikely, and if it were sanctioned, would definitely not have been accepted when the Imperium returned to the world after the war.

Thirdly, do you really think they'd let a human-eldar hybrid all the way back to Terra and be Soul-Bound to the Emperor? I mean COME ON?! THEN let him rise all the way up the ranks to become an advisor to the Adeptus Astra Telepathica?

Fourth, considering their proclivities for disdaining mutants and abhumans (not so much so in later editions) if the Dark Angels knew about him, they'd have something to say about it.

Fifth, after all this... holding the rank of Librarian means he'd be a Space Marine which at the point he joins the Ultramarines would have been all but impossible since he would have been past the age of admission, not to mention the potential corrupting impact it would have on the Ultramarine Gene-seed.

But, knowing 40K and GW, this is unlikely to be canon, especially since Varro Tigurius is the Chief Librarian during the dates that Nastase supposedly also holds the same rank... On the other hand, didn't they explicitly state that all official fluff is debatable and subjective, often potraying whoever are the heroes to their favour?

Love might just be able to bloom anyway. NOOOOOOOOO NO NOOOOO. BLAMBLAMBLAMBLAM HERESY!