Tarn was seemingly one of the hybrids who were born from Annihilation's forced breeding between her Daemons and the captured Okkaran Mutants. Tarn became a genomic mage able to manipulate the genes of his fellow mutants. He used his power to sculpt the bodies and powers of despised Amenthian mutants who pledged themselves to him. Many of them died through this process, but the ones who survived were under the servitude of Tarn whom they saw as their god, forming the Locus Vile. After Genesis became one with Annihilation, resulting in Arakko submitting to Amenth, Tarn and the Locus Vile made their residence on Arakko.
During the Amenthian occupation of Arakko, his Vile School Omnipaths monitored the Arakki populace, capturing anyone with dissident thoughts and sending them to the Abyssal Prisons where they were tortured. At some point Tarn claimed a seat on the Great Ring of Arakko, which he would defend from endless attempts to remove him.
X of Swords
When the Swordbearers of Arakko went to Otherworld to take part in the tournament which would allow Amenth to conquer Krakoa, the Hellions travelled to Amenth Krakoan Gateway, in hopes of stealing the Swordbearers' swords, but were too late and instead confronted by Tarn. Tarn figured out that Mister Sinister had actually come to Arakko in hopes of collecting the Arakkii's genes, and Tarn decided to show him his experimentations and let his Locus Vile loose on the Hellions. The Locus Vile were able to kill three of the Hellions, but Sinister managed to steal Tarn and the Vile's genes, sending the samples with the fleeing Hellions, much to Tarn's anger.
After the end of the tournament, Arakko was freed from Amenth's control, and after a brief attempt at re-union with Krakoa on Earth, was moved to a newly terraformed Mars, redubbed "Planet Arakko".
Tarn later raised the issue of Sinister's attempted theft of his genes during a meeting of the Great Ring, but the other assembled members refused to grant him leave to attack Krakoa. Tarn initially gave his word to leave Krakoa be, but would shortly thereafter renege on his promise, when his Locus Vile, now bolstered with the Sinister clone he had slain and then sewn back together, found Sinister and the Hellions. Tarn was summoned by the Vile and proceeded to make short work of the Hellions. He revealed Sinister's treachery to them, only for Sinister to release a dozen of his clones who proceeded to attack him. Tarn and the Locus Vile defeated the clones and tracked down Sinister and the clone, who had escaped to Sinister's secret clone factory. When Tarn found them, Sinister offered to show him the fruits of his labours; a clone of Tarn spliced with Sinister's DNA, granting Sinister access to Tarn's godlike powers. Before Tarn could destroy the clone, he was alerted to the fact that Amino Fetus had fed, causing it to proceed to the next stage of its cycle, a state that would cause the end of the universe. Tarn had Mother Rapture open a portal to a black hole at the edge of the universe, where he could safely destroy Amino Fetus. As he left, he vowed to return and mangle all the Hellions care for.
Shortly thereafter, a meeting of the Great Ring was called to discuss the consequences consequences of Tarn breaking his word. Tarn reiterated that he would not leave Krakoa alone until he was satisfied, prompting Storm, the newly-crowned Regent of Sol, to challenge him to a duel in the Circle Perilous. Tarn easily disarmed Storm, disabling her powers and mutating her grotesquely. Seemingly defeated, Storm managed to get close enough to pierce Tarn's chest with a dagger, threatening to kill him if he did not surrender. Tarn yielded and restored Storm's abilities and appearance, admitting that she was "of Arakko[... and] perhaps even of Amenth."
In order to get a sway in the Great Ring of Arakko's decisions, Abigail Brand persuaded Vulcan to challenge Tarn for his seat. During the fight Tarn and Vulcan turned off each other powers and started the physical brawl. Tarn quickly overwhelmed Vulcan and brutally killed him. Before he could leave the arena, Tarn was challenged again, this time by Magneto. Unbeknownst to Tarn, his doom had already been sealed, as Sunspot had tricked Isca into wagering against Tarn, meaning her ability to never lose would ensure his defeat. Magneto used his helmet to block Tarn's powers and then crushed his skull with it.
- Telepathy: Tarn is able to read the minds of individuals, although this causes pain to said individual.
- Teleportation: Tarn is able to teleport individuals through magic.
- Biological Manipulation: Tarn is able to manipulate the genes of mutants.
- Telekinesis: Tarn was able to tear apart the Mister Sinister clone with his mind.
- Tarn's abilities to manipulate biology is psychokinetic in nature. Magneto's Helmet was able to block Tarn from using his powers.
- Tarn's position as the Genomic Mage of Arakko is a parallel to Mister Sinister's role as Krakoa's geneticist.
- Tarn claimed to have once stolen "the voice" of Idyll the Future Seer.
- 7 appearance(s) of Tarn (Locus Vile) (Earth-616)
- 1 minor appearance(s) of Tarn (Locus Vile) (Earth-616)
- 3 mention(s) of Tarn (Locus Vile) (Earth-616)
- 16 image(s) of Tarn (Locus Vile) (Earth-616)
- 2 quotation(s) by or about Tarn (Locus Vile) (Earth-616)