Torgaddon paid the ultimate price for his loyalty and was slain by his once close friend and fellow Son of Horus, Captain Horus Aximand.
Later, samples of his gene-seed and fragments of his body were possessed by the Daemon known as Tormageddon, though the summoning ritual also reawakened a portion of Torgaddon's consciousness in the Immaterium.
Tarik Torgaddon was one of the four members of the XVIth Legion's Mournival, the fellowship of Astartes officers who served as the primary advisers to the Legion's primarch, the Warmaster Horus. He was known for the possession of an impish sense of humour highly unusual for the usually grim Astartes and for playing practical jokes upon his fellow Luna Wolves.
When Garviel Loken was elevated into the Mournival following the death of Horus' favourite Hastur Sejanus, Torgaddon befriended him, and his light-hearted, impish nature tempered Loken's strict adherence to the Legion's rules.
Torgaddon helped Loken settle into his new role as a Mournival member and advisor to Horus and introduced Loken to the Legion's Warrior Lodge, of which he was a member, showing him that they were simply a way for Astartes of differing ranks and companies to come together as equals, which somewhat allayed Loken's suspicion of them.
When the 63rd Expeditionary Fleet responded to the distress call of Khitas Frome of the Blood Angels, Torgaddon's company was chosen to descend to the surface of the world nicknamed Murder and search for survivors.
Once on the surface, he struck up a friendship with the Emperor's Children Astartes Captain Saul Tarvitz but developed a dislike for the arrogant Lord Commander Eidolon, a feeling that became mutual after Torgaddon pulled rank as a senior Luna Wolves officer, berated him for letting his lust for glory cause needless death, and told him that Horus himself believed that Eidolon was an idiot.
After contact was made with the Interex, Torgaddon continued to act as the Captain of the 2nd Company and a chief advisor to Horus.
When the Warmaster was mortally wounded on the moon of Davin and people were crying out against the grief-driven killing of humans by the Astartes when they returned with the unconscious Primarch to the Vengeful Spirit, it was proposed by the warrior lodge to rid the fleet of these dissenting voices. Tarik refused to take part in what was tantamount to a discussion of murder and ultimately quit the lodge over it.
Torgaddon also strenuously objected to the decision by the Legion's officers to place Horus, after his wounding on the moon of Davin by the Chaos relic blade known as the Kinebrach Anathame during his battle with the Nurglite Eugen Temba, in the care of the Chaos Sorcerers of the Temple of the Serpent Lodge.
This objection, in which he was joined by Garviel Loken, split the Mournival and increasingly the Legion. It also brought Torgaddon the disfavour of First Chaplain Erebus of the Word Bearers Legion. Erebus soon replaced the Mournival as Horus' closest adviser after he was "healed" by the priests of the Serpent Lodge and was corrupted by Chaos.
Like Loken, Torgaddon refused to follow his brothers into the service of the Ruinous Powers, particularly as the XVIth Legion's warrior lodge soon became the primary conduit by which Chaos corruption was spread through the Luna Wolves at the behest of Horus and Erebus.
Torgaddon became even more uneasy after the Luna Wolves were renamed the Sons of Horus by the Warmaster following his resurrection on Davin in what Torgaddon and others saw as a monument to his ambition and pride. Torgaddon soon became distrusted by Horus and his other Mournival brothers First Captain Ezekyle Abaddon and Captain Horus "Little Horus" Aximand, who in their absolute loyalty to Horus were even willing to serve his interests over those of the Emperor.
Because of this distrust, Torgaddon was identified as a Loyalist within the Legion and sent alongside Loken to capture the world of Istvaan III from Slaaneshi rebels located in the planetary capital of Choral City. After Horus unleashed an orbital virus-bombing upon the planet in the hope of eliminating the Traitor Legions' remaining Loyalists before beginning his rebellion against the Emperor, Torgaddon was one of the survivors. He helped lead his fellow Loyalist Luna Wolves alongside Garviel Loken in the grim battle with the Traitor Legions that unfolded in the blasted ruins of the Choral City for several months after the virus bombing.
On the last day of the long Battle of Istvaan III, Torgaddon and Loken received word that their former Mournival brothers Abaddon and Aximand would be present on the planet's surface to oversee the final offensive against the Loyalists that would end in a planetary bombardment from orbit by the Warmaster's fleet.
In the hope that they could kill the betrayers and thus badly damage Horus' plans to revolt against the Emperor, they ambushed the pair at their landing site, but Abaddon and Aximand proved the stronger.
Torgaddon was grudgingly slain in single combat by Little Horus, while Loken was badly beaten by Abaddon and then buried in broken masonry as the massive, final orbital bombardment of Istvaan III began and killed the last remaining Loyalists on the blasted world's surface.
Torgaddon's gene-seed was later harvested by the Sons of Horus after his death and used by the Word Bearer First Chaplain Erebus, along with gene-seed from the Salamanders, Raven Guard, Iron Hands and the Traitor Legions taken at the Drop Site Massacre, in a Chaos ritual intended to summon Warp entities on Calth in 007.M31 during the Word Bearers' assault against the Ultramarines Legion.
"Tarik reborn, he-who-is-now-Tormageddon" was named amongst those summoned, alongside known Daemons such as N'Kari, Epidemius and Samus. Erebus also used a fragment of the actual body of Torgaddon to summon into realspace the Daemon that named itself Tormageddon.
But a side-effect of the ritual was that it also allowed a portion of Torgaddon's own soul in the Warp to regain some sentience and remain free of the Chaos taint.
Torgaddon's consciousness would communicate with his old friend Garviel Loken while he was on Luna becoming a Knight-Errant, helping him to find a way to move past the betrayal of his Legion and reenter the fight against the Traitors.