Possessor's History
Like all the Elders of the Universe, the Possessor's origin is lost in antiquity. What is known is that he is one of the oldest living beings in the universe, having been a member of one of the first of the universe's races to become sentient in the wake of the Big Bang. Virtually immortal, Kamo Tharnn has spent the eons since his self-awareness engaged in the pursuit and recording of all the knowledge of the universe. Eventually Tharnn founded a huge university and library on the planet Rus, and transferred the vast store of information he accumulated to a huge master computer. He then opened the doors of the academy of learning to knowledge-seekers from anywhere in the universe. Within a century, his institution of advanced knowledge was filled with scholars, students, and researchers from over a thousand different intelligent star-faring races.
For untold millennia, Kamo Tharnn was content to be the master librarian and chief administrator of the university, until finally one of the many research assistants brought to him an alien artifact of immense power called the Runestaff. Excited by such a find, Tharnn asked to examine the artifact to record the properties for the master computer personally. The researcher had already devoted a great deal of time and effort mastering the Runestaff's properties and did not want Tharnn to take credit for its discovery, and so refused him. Violence erupted, and Tharnn slew the researcher.
The senseless act unhinged the sanity of the usually peaceful master librarian, and he began to experiment with the Runestaff with reckless abandon. One of the properties of the Runestaff is the manipulation of life forces, and Tharnn accidentally dispatched the hundreds of thousands of students and faculty on his planet into the limbo-like pocket dimension "inside" the staff. Driven further insane by the ruin of everything he had strove for over the eons, Tharnn, now calling himself the Possessor of the Runestaff, presided over the still planet, paranoid that someone would come and take away from him his last remaining possession. The planet's edifices soon fell into disrepair, the master computer ceased to function, and a furry pre-intelligent humanoid race began to breed wildly and overrun the planet Rus.
Eventually, Tharnn's paranoia was vindicated when the Olympian god Hercules and the Asgardian goddess Sif journeyed to Rus to borrow the Runestaff in order to save the waning life force of the mortal Jane Foster. When the Possessor refused to let them use it, the gods stole it from him and returned to Earth. By the staff's power, Sif's godly life essence was transferred into Foster's body, while Sif's body and consciousness went into the dimension "inside" the staff. Once Foster was saved, the gods forgot about the Runestaff and its mad owner. The Runestaff lay in a hospital broom closet for months until the alien Stranger dispatched the mutant Darkstar to fetch it in order to use its power to thwart the null-life bomb that was threatening all existence. When Jane Foster accompanied Thor to Asgard, Sif's godly life essence overwhelmed Foster's, and Sif's body spontaneously returned from the pocket dimension, sending Foster's there in exchange. Upon her return to Earth, Sif continued to predominate and Jane Foster remained in the pocket dimension.
Kamo Tharnn, in the meantime, had discovered a spell to teleport the Runestaff back to him. While tinkering with his prize possession again, he inadvertently transferred the life essences of all of the individuals who had been trapped in the staff's pocket dimension (including Jane Foster) into his own immortal body. Eventually Thor, Sif, and Jane Foster's fiance, Keith Kincaid, traveled to the planet Rus in an effort to locate Foster. Rescuing Tharnn from alien invaders, they succeeded in exorcising all of the spirits trapped inside Tharnn's body and restoring them to their rightful forms. The experience seemed to restore Tharnn's sanity and, reunited with all of his fellow knowledge-seekers, he vowed to restore his university to its former glory and not use the staff selfishly ever again. Thor, Sif, Foster, and Kincaid left the planet Rus for Earth. Kamo Tharnn began the process of rebuilding his citadel of knowledge and dispatching his researchers to gather all the information necessary to bring the master computer databank up to date.
At some point, the Possessor somehow joined the group known as the Elders of the Universe. He next appeared during the Elders' scheme to slay the planet-devouring Galactus and thus destroy the Universe in a bid to attain expanded powers.Their plan failed due to the involvement of Galactus' former Herald, the Silver Surfer, and his ally, Mantis. The Possessor and the Elders were consumed by Galactus, and tried to destroy him from within, but they were instead flung into a black hole.
Contest of Champions
The Possessor took part in a contest of champions between the Elders of the Universe to decide who would keep the Iso-8 that was now abundant after the rebirth of the multiverse, his champions lost and he was eliminated from the contest.