User blog comment:Aryeh.wolfblade/The missing legions aka fergotten ones./@comment-3416287-20120119021813/@comment-3055683-20120119052117

Actually if you check out the Blood Ravens page under the section, 'Possible Connections to the Thousand Sons Traitor Legion', its been summed up pretty well. Especially the information from the Horus Heresy novel 'Age of Darkness'. The short story 'Rebirth' by Chris Wraight, revolves around a squad of Thousand Sons Space Marines that return to their devastated homeworld of Prospero after the sanctioned Scouring of Prospero carried out by Primarch Leman Russ and his Space Wolves. After the Council of Nikaea, and the rebukement of Magnus the Red, a recall order was transmitted throughout the Legion, with the bulk of the Legion being present on Prospero just before the events surrounding the Fall of Prospero happened. However, some of the Thousand Sons' legionnaires had survived as they had not arrived before these events occurred. This would include those Thousand Sons that had been sent away aboard their Legion's fleet elements such as Captain Menes Kalliston of the 4th Fellowship. Six months after the sanctioned action against their Legion, Captain Kalliston leads a squad of battle-brothers to the ravaged surface of their homeworld to seek for any signs of survivors or their beloved Primarch. Instead, the squadron of Thousand Sons are taken by surprise when they encounter a much larger force of World Eaters who are also on Prospero for their own nefarious reasons. In the ensuing conflagration, the majority of the squadron are killed, and their Captain is captured, by none other than the infamous Captain Khârn of the 8th Assault Company and Equerry to the Primarch Angron of the World Eaters. Only Revuel Arvida, a Sergeant of the 4th Fellowship and a member of the Corvidae Cult manages to survive. Like all Corvidae, Arvida is skilled in the psychic discipline of precognition and the determination of the likely probabilities of future events. Despite his bleak circumstances, Arvida knew - as only a Corvidae could know - that death would not find him on Prospero. That was no consolation for everything that had been lost, but at least it lent the task of planning his next move a certain urgency. He would survive and live to discover the true causes of his Legion’s destruction, and live to fight them. He would neither pause nor stumble until everything had been revealed to him, everything that would give him a weapon to employ. He is quoted as saying "Knowledge is power," suggesting another connection to the Blood Ravens (p.162). Ironically, the symbol of the Corvidae cult discipline is that of a black ravens head. Sergeant Arvida's ultimate fate is unknown.