User blog comment:Cryptomania/Graveyard Shift/@comment-1932673-20120507164525/@comment-5055812-20120509010318

Hmm... there seems to be some confusion about those two Primarchs. I found that topic very interesting a few months ago, so I had to read up on them and so I probably know what I am saying. (or not)

1. The Space Wolves did not kill one of the unknowns. I read about a conversation (I think it was Prospero Burns) where Leman Russ was talking to his Astartes. He said that every Primarch had a wyrd, ,or purpose. Leman Russ' wyrd was to be the Emperor's executioner, BUT it is also said that the Emperor himself destroyed one of the legions.

2. All 20 Primarchs were found during the Great Crusade. Another supporting fact is that Alpharius Omegon was the last to be found, thus nicknaming him the Last. This also meant that there were 20 Primarchs at the beginning who were eventually found by the Emprah after they ruled over their homeworlds (with the exception of Konrad Curze). That would mean that somehting happened in the middle of the Great Crusade to the Legions.

3. Shortly after the two legions' records were expunged, the Ultramarines grew in size to eclipse all other legions. Now I'm not saying that both the Legions were annexed into the Ultramarines, but I can deduce that some of them were put into the Ultramarines. (Interesting fact: The Unknown Legion's numbers were 2 & 11. 2 + 11 = 13, which is the Ultramarines' Legion number lol)

4. One of the two Primarchs were corrupted by Chaos because it is said that, "one was still innocent and pure." I doubt that would mean anything more than one being corrupted.

5. The statues for the lost primarchs on Terra were "vacant for a long time." They were gone for awhile. Also, these Primarchs may not be dead, but absent.