The Thunder Warrior storyline in The Outcast Dead really got my brain spinning. I developed a little pet theory here that might interest you guys. I am in no way implying "this is the way it is" or anything. It's just for fun.
Arik Taranis is the ur Primarch. The primarch before there were primarchs. The primarch of the Thunder Warriors, and by extension the ultimate badass primarch. As the Thunder Warriors were the template the big E used to build the Astartes, Arik was the template he used to build the primarchs. Here's my (purely anecdotal) evidence.
- It follows the unspoken rule of 40k : the further you go back in time, the more badass stuff is. In 40k the Astartes are reduced to chapters. Many of them have lost a number of their genetic enhancements. The Imperium is in shambles. The big E is a shell. But if you go back to the HH, you've got full power Astartes; the Imperium is at the top of it's game; the Emperor is ambulatory. If you go alllll the way back in time you end up with the C'Tan and the Necrontyr who are kind of the premier badasses of all time. Further, the Thunder Warriors are clearly stated to be more powerful than Astartes (the era of the TW was before HH). So it's not a giant stretch to assume that the TWs had a demigodlike leader in the form of a prototype primarch.
- In The Outcast Dead, it is stated that in no uncertain terms that there was no other living being in the galaxy save the Emperor himself who could have decoded the secrets of the geneseed as Arik eventually does. And he does it with like a RonCo Chemistry Set. That's a primarch level feat.
- Also in the Outcast Dead, it is strongly implied that the hyperbolic descriptions of the famous TW battles were not hyperbole. There is talk of Arik knocking down the "Azurite Tower" with his bare hands, and participating in mountain-sundering conflicts against techno-warlords. He has a laundry list of battle honors so long that even modern day Astartes are awestruck in his presence. These are the sorts of things you would attribute to a primarch.
- Ghota, his subordinate, fights 5 minor-hero level Astares essentially single-handedly to a stalemate, killing one of them. But he shows complete deference to Arik, implying he knows he is a lesser being.
- It would seem that Arik is at least several centuries old. And despite not being built to have the longevity of Astartes, he is somehow still alive. This seems to imply an extra level of potency you might expect to see from a particularly exceptional version of a TW.
- At the very end of the story when he successfully completes his research into the geneseed and Ghota asks "did it work?". He answers "Yes, my son." This is the sort of way you expect a primarch to address one of his, well, sons.
Edit : forgot one of the most important things. When Arik reveals himself in the temple, he projects an "aura too bright to look upon. His presence had a gravity all it's own, demanding all attention and fear." Atharva, a powerful Thousand Sons psyker "could barely stand to turn his psychic senses on him for fear of being overwhelmed." This is exactly the sort of ensorcellating aura that is associated with primarchs, and the Emperor.
Arik Taranis is the ur Primarch. The primarch before there were primarchs. The primarch of the Thunder Warriors, and by extension the ultimate badass primarch. As the Thunder Warriors were the template the big E used to build the Astartes, Arik was the template he used to build the primarchs. Here's my (purely anecdotal) evidence.
- It follows the unspoken rule of 40k : the further you go back in time, the more badass stuff is. In 40k the Astartes are reduced to chapters. Many of them have lost a number of their genetic enhancements. The Imperium is in shambles. The big E is a shell. But if you go back to the HH, you've got full power Astartes; the Imperium is at the top of it's game; the Emperor is ambulatory. If you go alllll the way back in time you end up with the C'Tan and the Necrontyr who are kind of the premier badasses of all time. Further, the Thunder Warriors are clearly stated to be more powerful than Astartes (the era of the TW was before HH). So it's not a giant stretch to assume that the TWs had a demigodlike leader in the form of a prototype primarch.
- In The Outcast Dead, it is stated that in no uncertain terms that there was no other living being in the galaxy save the Emperor himself who could have decoded the secrets of the geneseed as Arik eventually does. And he does it with like a RonCo Chemistry Set. That's a primarch level feat.
- Also in the Outcast Dead, it is strongly implied that the hyperbolic descriptions of the famous TW battles were not hyperbole. There is talk of Arik knocking down the "Azurite Tower" with his bare hands, and participating in mountain-sundering conflicts against techno-warlords. He has a laundry list of battle honors so long that even modern day Astartes are awestruck in his presence. These are the sorts of things you would attribute to a primarch.
- Ghota, his subordinate, fights 5 minor-hero level Astares essentially single-handedly to a stalemate, killing one of them. But he shows complete deference to Arik, implying he knows he is a lesser being.
- It would seem that Arik is at least several centuries old. And despite not being built to have the longevity of Astartes, he is somehow still alive. This seems to imply an extra level of potency you might expect to see from a particularly exceptional version of a TW.
- At the very end of the story when he successfully completes his research into the geneseed and Ghota asks "did it work?". He answers "Yes, my son." This is the sort of way you expect a primarch to address one of his, well, sons.
Edit : forgot one of the most important things. When Arik reveals himself in the temple, he projects an "aura too bright to look upon. His presence had a gravity all it's own, demanding all attention and fear." Atharva, a powerful Thousand Sons psyker "could barely stand to turn his psychic senses on him for fear of being overwhelmed." This is exactly the sort of ensorcellating aura that is associated with primarchs, and the Emperor.