The Flesh Tearers' blood-rage is infamous across the Imperium, as are the savage deeds said to have been performed by their battle-brothers. So divorced have the Flesh Tearers become from the rest of Mankind that most Imperial Commanders accept the Chapter's help only in the direst of circumstances. Eventually they do make it out of the warp. But then they bounced into the whole Badab situation. After that, they bounced right into the “jaws of Hive Fleet Kraken.” They managed to survive with 3 companies… Dante asked the High Chaplain why he would stand in Seth's defence. Seth had troubled him, even bloodied him on a prior visit to Baal, and on more than one occasion. Astorath explained that they were the Emperor's avenging angels. They showed no mercy. No forgiveness. They had been bred to bring only death. They were terrible to behold and their fury was the stuff of fire-swept legends. Yet, there were terrors in the depths of the universe whose might eclipsed their own, whose hatred they could not comprehend. There were foes they must face who would cross the lines of honour and kinship that they could not afford to break. When Flesh Tearers battle-brothers show the characteristic signs that they are falling prey to the Flaw, they are inducted into the Chapter's Death Company and isolated from their healthier brethren. These Space Marines continue their service under the supervision of the High Chaplain of the Death Company, residing in the specially-adapted strike cruiser Death's Cowl until they are called upon.

Shield of Baal - Exterminatus (Campaign Supplement), pp. 10, 21, 27-28, 32, 42, 45-47, 49-50, 279-280, 317, 334-335Chief Librarian Mephiston's personal banner, presented to him following his heroic exploits on the Hive World of Hollonan. Like their fellow Astartes Chapters, the Flesh Tearers also maintain a Librarium of potent psykers who are highly talented and trained to master the power of the Warp at the highest levels. Each Chapter selects its Librarians in its own way, either from seed worlds, as it does with the bulk of its Initiates, or from the ranks of gifted psykers brought to the Scholastica Psykana of the Adeptus Astra Telepathica.

At some point after the birth of the Great Rift Mephiston willingly underwent the torturous surgical procedure of the Rubicon Primaris and ascended to become a Primaris Space Marine. They are true servants of the Emperor of Mankind though their heavy affliction with the genetic flaws of their Primarch Sanguinius and the resulting brutality has led to their investigation on charges of heresy by the Inquisition. They have been cleared of suspicion at present. Many Chapters have become wary of the Flesh Tearers, with their dire reputation for unrestrained carnage and their excesses of violence. However, to Dante the Flesh Tearers were still his brothers, born of the blood of Sanguinius, and worthy allies in the war against the Hive Mind. The fact that Seth led the Flesh Tearers to the Cryptus System in such strength speaks volumes about the bond between his Chapter and the Blood Angels. It was a desperate hope at best until the arrival of the Indomitus Crusade on Baal and the inclusion of the Primaris Marines in the Flesh Tearers' ranks. Now Seth has a new fear -- that when his Chapter has lost their defining rage, they may transform into something different...something less than the true scions of Sanguinius. Whilst fighting before the walls of Hades Hive, during the Second War for Armageddon, the curse of Sanguinius finally stole upon him. Inducted into the Blood Angels' Death Company, Calistarius took part in the final assault on the Ecclesorium building at Hades Hive, and was amongst those buried when the complex collapsed.Seth informed the assembly that he had come to make a sacrifice, but one that would include him alone. They might damn him, removing his name and deeds from the histories of the Imperium. But they would spare his Chapter, he warned. Dante informed the Flesh Tearer that he was in no position to make demands. Castellan Zargo, Chapter Master of the Angels Encarmine, agreed with the Lord Commander, pointing an accusatory finger at Seth, warning him that he would account for his deeds. Seth interjected, yes, he would -- but only his deeds. And with him it would end. Red Scar Campaign (Unknown Date.M42) - Hurled across the void by an empyric convulsion, a T'au colonisation fleet began claiming worlds within the Red Scar. Their efforts were brought to a sudden, violent halt by strike forces of Blood Angels, Flesh Tearers and the Angels Sanguine. The planets of D'sandri and Gendal's Reach were swiftly reclaimed, and the war spilled into the Sevensuns System. Dante slammed his hand down, brooking no more dissent from the assembled scions of Sanguinius. The Flesh Tearer had said his piece, now Seth would listen to what the assembly had to say. Dante gestured to Techial, Chapter Master of the Disciples of Blood. He had been appointed the assembly's Chronicler. It fell to him to recount Seth's sins, to detail the actions that had brought the Flesh Tearers to such a juncture. Techial unfurled a length of parchment and read the charges aloud. Achilus Crusade (813.M41) - A Flesh Tearers strike force based around elements from the 1 st and 2 nd Companies arrived unheralded during the Achilus Crusade in the Jericho Reach around the world of Herisor, soon after the first tendrils of Hive Fleet Dagon hit the Orpheus Salient. The Chapter fought a series of actions trailing along the salient, intercepting tendrils of the Hive Fleet and buying time for other Imperial forces to muster a defence. The Chapter took heavy losses in these actions, yet refused to slow the pace of its operations, throwing itself into battle after battle against the ravening xenos monstrosities that were the Tyranids.

The Flesh Tearers would prove their reputation for ferocity many times over on the battlefields of Lysios, the Space Marines venting their fury upon the Tyranids in a maelstrom of blood. Supported by the Chapter's finest war machines, theirs would be a horrific war of annihilation upon which they would seek to quench their Red Thirst. But beneath their boisterous behaviour and irrepressible wildness, the Space Wolves are as valiant as any other Space Marines, despite their disdain for the dictates of the Codex Astartes. Instead of Guilliman-approved battle formations, they form their warriors into specialist units like Wolf Guard and Blood Claws, even in the age of Cawl’s Primaris Space Marines. In 837.M41, Inquisitor Corvin Herrold of the Ordo Hereticus boarded Victus, the flagship of the Flesh Tearers, seeking an audience with Chapter Master Gabriel Seth, officially to question Seth about the recent events at the Shrine World of Lucid Prime, where the Flesh Tearers had been involved in a bloody confrontation with the Space Wolves after they had continued to kill civilians they claimed were corrupted by Chaos.Their reputation for such savagery has spread through the millennia to the extent that some forces -- including several other Space Marine Chapters -- are no longer willing to engage in allied missions with members of the Flesh Tearers. In spite of this fact, there are numerous instances where the Flesh Tearers have worked in battle zones with other Chapters. On a number of occasions, these included other Chapters that were known to be part of the Blood Angels lineage. For all his efforts to challenge the commonly held perceptions of his Chapter as berserk butchers, Gabriel Seth is every bit the bloody whirlwind when he plunges into battle.