Alpharius Omegon - Post-Heresy: During the Horus Heresy, Alpharius Omegon appeared more interested in proving his own Legion's worth by fighting, at every chance he got, the best of the Loyalist Legions. In the aftermath of the Horus Heresy, the Alpha Legion did not retreat to the Eye of Terror like the other Traitor Legions; instead they moved on to the galactic East, following new objectives of their own devising. Whether or not being brought to battle with the Ultramarines was one of these objectives is unknown, but it occurred all the same.It was on the world known as Eskrador that Alpharius and Roboute Guilliman would meet for the last time. Believing that Guilliman would adopt his standard deployment procedures as later outlined in the Codex Astartes, Alpharius was surprised by the Ultramarines, as a splinter force including their primarch made a quick strike at the Alpha Legion's headquarters. Alpharius was reportedly happy with such a development, as it allowed him to demonstrate the superiority of his flexible, multitudinous and unexpected military strategies over the notoriously precise, methodical and perhaps even tactically moribund Ultramarines.Both primarchs met in combat and Alpharius was killed. Believing the combat over, for what Astartes Legion could ever survive the loss of their primarch in battle, the Ultramarines were taken by surprise by the remaining elements of the Alpha Legion, when they struck back a solar day later. The Ultramarines who had launched the attack on the Traitor Legion's headquarters were harried so mercilessly that by the time they had returned to the main body of the Ultramarine force their casualties were almost total.After a solar week of constant fighting and heavy losses, the Ultramarines' strike force managed to reunite with their main elements, and quickly evacuated the planet. Even though they had lost their primarch, the Alpha Legion had soundly beaten the Ultramarines, who proceeded to bombard their foes' position from orbit. It should be noted, however, that Alpharius' death is still considered suspect even by the Ultramarines, and he may still be at large.Unlike the other Traitor Legions, most of the Alpha Legion in the wake of the Horus Heresy does not reside in the Warp, but rather roams the galaxy in warbands of warriors, each of which is trained to act independently of each other in pursuit of their greater cause. In this way the Alpha Legion was by and large the only Traitor Legion not to succumb to the mutations of Chaos, an outcome that may also have been dictated by their possible continued secret loyalty to the Emperor of Mankind.Following the Battle of Eskrador, the Alpha Legion fractured in order to hide from the Imperium. Small, autonomous warbands were left in Imperial space where they set up secret bases in asteroid fields, Space Hulks, and barren, unpopulated worlds. These units launched frequent attacks against military targets that were weakened by the Heresy and even today still pose a threat to Imperial starships, settlements, and garrisons. The Alpha Legion's warbands also spread and coordinate Chaos Cults throughout the galaxy in order to instigate massive planetary revolts against Imperial rule. These insurrections are often used to lure Imperial forces away from worlds the Alpha Legion wants to attack, paving the way for large-scale assaults of Heretic Astartes from the Eye of Terror.The Alpha Legion's role in spreading heretical Chaos Cults across the Imperium has earned them the loathing of the Inquisition, whose Ordo Malleus and Ordo Hereticus have devoted considerable resources to finding and destroying their secret bases. The Alpha Legion has been declared wiped out by the High Lords of Terra no fewer than three times, in the 31st Millennium, the 32nd Millennium and the 39th Millennium.These claims have always been disproved by the continued assaults of the Legion. The Alpha Legion has suffered heavy casualties on many occasions since the end of the Heresy, yet its continued large numbers has led many Imperial observers to conclude that they are recruiting new members into the Legion and thus have managed to maintain a supply of untainted gene-seed, also a rarity for Chaos Space Marines.