Primaris Blood Angels and their 'flaws'
Something i wanted to share from clonelord. Fabius makes a note of that he had discovered that the Primarchs stored their memmories in their blood and bone, in a process that he had not managed to replicate. But that, more than anything else was how he had managed to recreate the primarchs, and how they would eventually begin to remember themselves even when cloned. Fabius had expended many resources to aquire genetic material from all of the Emperors sons.
So, for Blood Angels its pretty clear now, due to them supping on their fathers blood, they are essentially drinking his memmories. Whereas Cawl had considered the red thirst one of the Emperor's intentional idiosyncracies and left it alone, as the Primaris Bangels are suffering from that flaw. But with Guiliman having given Cawl a superior source of the genematter of the primarchs, the artifact the Sangprimus Portum, containing superior genematter of all the primarchs. So it would never have the tainted blood from sanguinius himself.
The Sangprimus Portum is an Imperium artefact, that contains the genetic material of all twenty of the Emperor's Primarchs. In the aftermath of the Horus Heresy, the Primarch Guilliman gave the Sangprimus Portum to Archmagos Dominus Cawl, after charging the Archmagos with creating the next generation of Space Marines. Cawl succeeded and the unleashed Primaris Space Marines are taller and stronger than their Space Marine brethren, due to the fact that the genetic material within the Sangprimus Portum was even more potent than the Gene-Seed descended from the Primarchs.