Chaos Ascendant
The Warmaster's assault on Altec was at the final stage of preparations, when Primarch Itou Makoto of the Scarlet Hydras demanded the honor of leading the assault. Lelouch, figuring that victory on Altec was already all but assured, allowed the Primarch overall command over all four traitor Legions involved in the assault. After all, he reasoned, it would be hard for even Itou Makoto to fail in a situation where his forces enjoyed absolute advantages over the outnumbered defenders. Also, he believed that Makoto's lieutenant commanders, Kotonoha and Sekai, would be able to talk sense into the incompetent Primarch should the need arise. Happy with his new authority, Primarch Itou threw the power of all four Legions simultaneously upon the doomed planet.
The initial landings by the Chaos Space Marines were hotly contested, as the Crossed Scars, personally led by Primarch Sagara Sousuke, utilized their infiltration and guerilla skills to devastate the traitors' ranks before they could regroup, while orbital defense guns shot down scores of drop pods and Thunderhawks that the traitors were using to gain a foothold on the surface. However, these initial successes were not to last; as the massed traitors began landing across the entire planet, even the Crossed Scars were eventually forced to pull back and regroup in the vast Factory-Citadels that dotted Altec's surface.
Thus began the grueling and non-stop combat across the length and breadth of the continents of Altec. Each Factory-Citadel was heavily fortified and defended by Imperial Guard Regiments and Astartes who manned the defenses against a seemingly unending tide of heresy and insanity. Chaos Space Marines assaulted the citadels, only to be thrown back by a storm of fire and steel that Primarch Nanoha would have been proud of. Companies of the Crossed Scars and Orange Legion dispersed into the vast badlands of Altec, where they mounted hit-and-run attacks upon the enemy encampments. For the moment, it seemed that the traitors' superior strength of numbers was balanced by the well-fortified and highly defensible positions that the loyalists possessed.
However, as the days stretched into weeks, the situation began swinging heavily in favor of the traitor Legions. While Altec's factories could produce all the munitions and weapons that the loyalists would ever need, it relied upon imports for food supplies. The Astartes on both sides were able to live off the land thanks to their superhuman capabilities and training, but the Imperial Guard regiments were all too human. The enemy naval fleet had embargoed the planet since the start of the assault, and food supplies were already running dangerously low across all Factory-Citadels. Imperial citizens shared what they could with their protectors, but that could not prevent the inevitable. It seemed that Primarch Itou's impromptu plan of starving the Imperial loyalists to death was working all too well.
Similarly, the situation across the Imperium was becoming increasingly desperate, ever since the assault upon Altec started. Four out of the twelve targeted capital worlds had fallen to the forces of Chaos despite the best efforts of the Imperial loyalists, and the armies of the Imperium were sent reeling as numerous other planets fell in rapid succession to the rest of Warmaster Lelouch's forces. To aggravate the situation, formerly loyal worlds began declaring independence from Imperial rule, defying both the Empress and Lelouch in a bid to carve their own destiny. Planetary Defense Forces were left unsure of their commanders' ultimate loyalties, and whole planets fell into turmoil with little provocation. Entire units were cast in doubt or suspicion regardless of their allegiance, and Lord Koizumi's Imperial Inquisition was stretched to its considerable limits as it strove to separate loyalty from heresy.
The Warmaster's traitor Astartes Legions marched triumphantly through the chaos of it all, driving disorganized loyalist Imperial Guard and Navy units before them. The loyalist Astartes Legions such as the Imperial Fists, Empress' Children and White Wings performed admirably while defending against the traitorous onslaught, but even they could only stem the tide for so long before attrition from constant combat began to set in. Each Primarch knew that without the full power of the remaining loyalist Legions, it would only be a matter of time before the Imperium was overrun and Terra open to attack, but still they fought on for Humanity and the Empress, hope in their hearts and weapons in their hands, their respective Astartes Legions loyally with them.
Meanwhile, the Imperial forces were in danger of losing Altec entirely. Already, some garrisons were down to less than a week's worth of food supplies, with some Factory-Citadels subsisting on nothing more than their faith in the God-Empress. The loyalist Astartes continued their attacks on the betrayers, but they were too few in number to cause significant damage to entire Legions' worth of traitor Astartes and war machines. It was also getting increasingly harder for the Crossed Scars and Orange Legion to return to friendly lines for ammunitions and necessary supplies, as the traitors spread out across the entirety of Altec and occupied more and more of the planet's surface. The only bright light in an otherwise bleak situation was the Imperial Navy's success in preventing the Warmaster's Navy from claiming total control in the orbital space around Altec, though every commander on both sides knew that the battle would ultimately be decided on the planet itself, rather than in the vacuum of space.
So it was that Altec, and the Imperium as a whole, were seemingly destined to fall into the talons of Lelouch, and through him, the clutches of the Chaos Gods. Lelouch laughed in his mania, confident in the superiority of his tactics, and began making ready his plans for the Siege of Terra, where he would confront the false Empress and destroy Her once and for all. Then the latest reports flooded in, and he began to suspect that his plans for Terra would be delayed for a while.