- "I see fear in their eyes, right before they die. I see shock as they realise too late what it is to pit their pitiful strength against true power."
- — Chaos Lord Kranon the Relentless
Kranon the Relentless is a Chaos Lord and the current leader of the Crimson Slaughter warband of Chaos Space Marines. Once the Loyalist Astartes named Sevastus Kranon, he was a militant and brutal warrior even when he was still a servant of the Emperor of Mankind as the Chapter Master of the Crimson Sabres Chapter of Space Marines. The Crimson Sabres eventually slid into heresy and damnation following the massacre committed by the Chapter on the world of Umidia. Cursed by the Blood God Khorne, the Crimson Sabres were driven insane by voices in their heads which belonged to their murdered victims. Upon leading his warband into self-imposed exile in the Eye of Terror, Sevastus was finally corrupted by the Ruinous Powers of Chaos. Renaming himself Kranon the Relentless, he has driven himself and his Chapter to commit increasingly bloody and vile acts in an attempt to silence the maddening voices that plague him and the rest of the Crimson Slaughter.
Sevastus Kranon was once Chapter Master of the Crimson Sabres Space Marines. Under his command the Chapter won great accolades, crushing whole worlds in the name of the Emperor. His brutal manner, however, earned the Crimson Sabres a dark reputation in the broader Imperium. The Crimson Sabres' descent towards excommunication began on the Jungle World of Umidia, where the Astartes conducted a genocidal purging of the Balethu Cults in 928.M41. Subsequent interrogation of captured Crimson Sabres revealed that the Chaos Cults of Umidia were in the process of summoning a daemon of Khorne, and in their rush to judgment, the Crimson Sabres purged the entire planet of life. In revenge (or possibly reward) for the bloody annihilation of his followers, Khorne cursed the Crimson Sabres to be haunted by the voices of all those they had slain.
The entire Chapter was literally haunted by the butchery of the mysterious Balethu; poltergeist activity surrounded the Crimson Sabres wherever they went. Whenever a Space Marine closed his eyes, he could see the faces of those he had killed and hear their screams in his mind. Sleep became impossible and, slowly at first, a pall of paranoid insanity spread through the Chapter like a disease. This led the Crimson Sabres to being declared Renegades by the Inquisition and the High Lords of Terra due to the signs of continued psychological instability the Astartes of the Chapter displayed and their continued penchant for over-zealous prosecution of their campaigns.
In an attempt to burn away the harrowing memories in the fires of war, Chapter Master Sevastus Kranon declared the neighbouring world of Demetra tainted by mere proximity to Umidia, and the killing began anew. The desperate plan worked, for the spectres of the Balethu were drowned out in a series of gore-drenched battles. Subsequent bloodshed could silence the voices, but only for a short time. Kranon then led his warriors into the Eye of Terror to slaughter Traitors instead of spilling the blood of Imperial innocents, thereby gaining a temporary respite. Exiled in the Eye of Terror, the Crimson Sabres were blessed with many gifts by the Ruinous Powers to further their combat prowess. They were finally fully corrupted by Chaos and remade themselves as the warband of Chaos Space Marines called the Crimson Slaughter.
Sevastus Kranon, reborn as the Chaos Lord and Champion of Khorne named Kranon the Relentless, learned of the mystical Chaotic artefact known as the Hellfire Stone, an altar dedicated to Khorne that could forever free his Astartes from their curse and silence the voices in their heads once and for all. It was said that once anointed with the blood of a Space Marine, the Hellfire Stone would open a doorway into the Warp and allow a powerful daemon to pass through into realspace. Joining forces with warbands drawn from the Traitor Legions during the 13th Black Crusade, Kranon and the Crimson Slaughter began their rampage across multiple Imperial worlds in their relentless search for the Hellfire Stone.
Carving a bloody swathe across the dozen or more populated worlds that dotted the southern rim of the galaxy, the Crimson Slaughter overwhelmed Imperial garrisons and slaughtered whole populations before vanishing into the Warp once more. Although their rebellion against the Imperium had been well documented -- if subsequently suppressed by order of the Inquisition -- the remote nature of the planets they attacked meant that by the time a distress call was answered, the Crimson Slaughter had long departed.
This remained true until the Crimson Slaughter made the mistake of engaging the Dark Angels' 5th Company in battle upon the world of Stern's Remembrance, slaying many Battle-Brothers including the 5th Company's Master, Zadakiel. Such an act of violence earned the undying enmity and wrath of the Dark Angels and the newly ascended 5th Company Master, Balthasar, who swore to hunt down those responsible for his predecessor's death and bring their heads back to The Rock, the spaceborne fortress-monastery of the Dark Angels. The 5th Company was also accompanied in this task by members of the Dark Angels' elite 1st Company, the Deathwing, members of the 2nd Company, the Ravenwing, and a powerful Librarian named Turmiel, who had been trained by Ezekiel, the Chief Librarian of the Dark Angels. Relentless proved the Dark Angels' hunt across a dozen worlds, until finally the Chaos Space Marines were tracked to the world of Bane's Landing where they were confronted by the Dark Angels 5th Company once more. Kranon the Relentless sought to use the Hellfire Stone he had finally discovered there to summon forth his daemonic masters and usher in a new age of darkness. As the Dark Angels raced to stop him, a mighty conflict between the loyal Balthasar and the Traitor Kranon was in the offing.
- Crimson Slaughter - A Codex: Chaos Space Marines Supplement
- White Dwarf 393, "Dark Vengeance", pp. 22-35, 40-65
- White Dwarf 392, "The Crimson Slaughter," "'Eavy Metal - Chaos Space Marines," and "The Battle for Bane's Landing," pp. 32-33, 38-63
- Ascension of Balthasar (Audio Drama) by CZ Dunn
- Dark Vengeance (Novel) by CZ Dunn