13th Black Crusade - The Battle of Kasr Holn: The Forces of Chaos continued to hit Imperial forces hard across the entire region surrounding the Eye of Terror. The Fortress World of Kasr Holn, one of the outer planets of the Cadia System, had borne the brunt of the Chaotic ground assault on Cadia over a number of solar days, with wave after wave of frenzied mutants assaulting the walls of the Fortress World's capital city. Fifteen regiments of Cadian Shock Troops manned the defences there, and an entire Legion of the Adeptus Titanicus was deployed. Were it only the seemingly endless hordes of ill-disciplined mutants attacking Kasr Holn's capital, the Imperial defenders might have been able to contain them there, but the assaults were led by none other than the Traitor Astartes of the Black Legion.The Black Legionaries were content to allow the thousands of mutants to crash against the Kasr Holn capital's defences, in order to wear down and deplete their materiel stores through sheer attrition. Each wave had been repulsed, but only at the cost of many brave defenders, and with little or no affect on the Archenemy force's numbers. Just when the attackers were sent once more into an undisciplined rout, the Black Legionaries launched their own attack. These attacks cost the Imperial defenders dear, though fortunately they were unable to pierce the defenders' lines. Yet with each successive wave they were only able to kill a handful of the enemy, while the casualties the defenders sustained were intolerably high.Lord Castellan Ursarkar E. Creed moved his headquarters from Cadia to Kasr Holn to counter the crisis rapidly developing there, believing that his inspiring presence would make the same difference as the addition of several regiments. He led a bold counterattack at the head of the Cadian 8th Regiment, "the Lord Castellan's Own," against the Forces of Chaos, sallying forth with the Imperial forces once the latest wave of mutants had receded, and struck at the Black Legion before the Chaos Space Marines' own assault could develop. This Imperial counterattack was a resounding success, and as Creed returned to the walls of Kasr Holn's capital at the head of the 8th Cadian, the entire length of the eastern wall erupted with the cheers of many thousands of men. But soon the Battle of Kasr Holn took on a new and unanticipated turn, one that could scarcely be believed had it not been witnessed personally.At the height of the next assault of the mutants upon the eastern wall of the Kasr Holn capital city's primary fortress, at the moment when it appeared as if the Black Legion would force a breach, the feral 13th Great Company of Space Wolves appeared from behind the Traitors' lines and inflicted a crushing defeat upon them. Both the Chaos attackers and the Imperial defenders heard with their own ears the animalistic howls emitted by these barbarous warriors, even though many were at their station some distance from the fighting. The sound chilled everyone who heard it to the core. Fortunately, the affect upon the enemy was greater still. The vile mutants fled first, turning their backs and fleeing in an instant.Their Black Legion masters attempted to forestall the rout, firing upon the mutants in an effort to render them more terrified of their own masters' retribution than they were of the 13th Company. But their efforts were wasted, and many Black Legionaries were trampled as the mutants stampeded from the walls. Soon, the Black Legionaries were themselves assaulted, and those not cut down from the rear were forced to quit the field, an event unheard of to date for the fierce Chaos Space Marines of Abaddon's own Traitor Legion. The 13th Company's attack was over almost as soon as it had begun, and they soon withdrew, making no attempt to communicate with the other Imperial forces as they did so.