Early Life[]

Tarn was seemingly one of the hybrids who were born from Annihilation's forced breeding of her Daemons and the captured Okkaran Mutants.^[5] Tarn became an Omega Level mutant and sorcerer capable of manipulating the genes of his fellow mutants. He used his power to sculpt the bodies and abilities of despised Amenthian mutants who pledged themselves to him. Many of them died through this process, but the ones who survived served Tarn without question, worshipping him as a god. They became known as the Locus Vile.^[6]

Tarn became the lover of Isca the Unbeaten, an Okkaran mutant who had been compelled to defect to the side of Amenth by her powers, which made her unable to lose. ^[7] After Genesis became one with Annihilation, resulting in Arakko submitting to Amenth,^[5] Tarn and the Locus Vile made their residence on Arakko.

During the Amenthian occupation of Arakko, Tarn's Vile School Omnipaths monitored the Arakkii populace, capturing anyone with dissident thoughts and sending them to the Abyssal Prisons where they were tortured. Tarn oversaw the prisons, and became a loathed figure in Arakko. ^[8] At some point Tarn claimed a seat on the Great Ring of Arakko, as an insult to all those who endured his tortures rather than bend their knee to Annhilation. He would defend his seat from endless attempts to remove him.^[9]

X of Swords[]

When the Swordbearers of Arakko went to Otherworld to take part in a tournament which would allow Amenth to conquer Krakoa, the Hellions of Krakoa travelled to Amenth in hopes of stealing the Swordbearers' swords and winning the tournament by forcing Arakko to concede, but were too late and instead confronted by Tarn. Tarn figured out that Mister Sinister, leader of the Hellions, had actually come to Arakko in hopes of collecting the Arakkii's genes, and decided to show Sinister his Locus Vile. When Sinister unleashed a swarm of mechanical mosquitoes which took samples of Tarn and the Locus Vile's genes, an enraged Tarn unleashed the Vile on Sinister and the Hellions. The Locus Vile were able to kill three of the Hellions and Sinister himself (who unbeknownst to Tarn was merely a clone), but the remaining Hellions managed to escape with the stolen genes.^[6]

Planet Arakko[]

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".^[10]

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.^[11] Tarn and the Locus Vile defeated the clones and tracked down Sinister, who had escaped to a secret clone farm. 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 that the Hellions cared for.^[12]

Shortly thereafter, a meeting of the Great Ring was called to discuss the consequences of Tarn breaking his word. While the Sinister clone made from his DNA had been destroyed, Tarn reiterated that he would not leave Krakoa alone until he was satisfied, prompting Storm, the recently-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. Unwilling to risk death, Tarn yielded and restored Storm's abilities and appearance, admitting that she was "of Arakko[... and] perhaps even of Amenth."^[2]

In order to secure influence over the Great Ring of Arakko, Abigail Brand persuaded Vulcan to challenge Tarn for his seat.^[13] The two negated each other's powers, but 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.^[1]

Afterlife[]

In the Waiting Room, while Tarn discovered that many souls decided to leave the Waiting Room for true death in the Well Beyond the Worlds, he himself decided to wait until he could himself be resurrected. When Storm came to try to resurrect Magneto, he cryptically told her what happened to the rest of the mutant souls waiting for resurrection. When Storm announced her intention to resurrect Magneto, Tarn was enraged and attacked her, transforming into a horrific creature using his own powers onto himself, but was still defeated by Storm.^[4]

Tarn is a sadist of the highest order, who delights in nothing more than tormenting and perverting the very beings of his victims. Tarn considers himself a god and his touch a sacrilegious blessing, carving his stamp into the genomes of his worshippers. The only ones who fear Tarn more than his victims are his followers, who worship him as a living god, consider him their father and exist only to usher him to new lands, where he may spread his perversions.^[6][12]

As a result of his godlike powers, Tarn is arrogant and frequently toys with his challengers, deforming their bodies and robbing them of their powers before killing them. Tarn is vengeful and will go to great lengths to punish any perceived affront to himself or his great works.^[2]

Tarn the Uncaring was an Omega-level Amenthian mutant/daemon hybrid with magic powers:^[6][8]

• Psychokinetic Biological Manipulation: Tarn was able to manipulate DNA with his mind, including his own. Applications of this include depowering, empowering, and giving new powers to mutants; reversing aging; and disfiguring others with a thought.^[2] Tarn also appears to have some level of telekinetic control over biological materials.^[6][14]
• Telepathy: Tarn was able to read the minds of individuals, although this causes pain to said individual.^[6][14]
• Superhuman Strength: Even without his abilities, Tarn possessed strength far greater than that of a normal human and could break Vulcan's arm with ease.^[1]

• Tarn's abilities to manipulate biology is psychokinetic in nature. Magneto's Helmet was able to block Tarn from using his powers.^[1]

• Tarn superiority complex caused him to falter and lose battle trice; twice in the Circle Perilous, which led to his death. The third time facing Ororo again in the Waiting Room.^[2][1]

• Teleportation: Tarn was able to teleport via Mother Rapture's Blade Fish.^[11]

• 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.