Join Date: May 2009
Location: South Carolina, USA
Actually, there is some very specific 'voodoo' required for standard astartes.
It is called geneseed.
They cannot produce more geneseed from scratch, as it requires already mature geneseed to grow more in the body of a new astartes. Much to the dismay of Legions that suffered great losses in the heresy.
No geneseed, no astartes. Geneseed is a direct genetic line back to the first astartes, the Primarchs, and the Emperor's original 'voodoo'.
It might not require a pysker to install it, but it sure was created by one of the greatest psykers to live.