Whilst in South America to claim a fortune left to him by an uncle, Tim Kelly is taken prisoner and sold into slavery. Kelly is with a group on a forced march when he rescues another slave, an old man after he is thrown into a piranha infested swamp by their captors, the two manage to escape.
The old man turns out to be an Incan shaman, and takes him to the Temple of Zoltec, where, while exploring, Tim finds a gem named the Eye of Zoltec, which he discovers makes him invulnerable to all harm, as well as enhancing his speed, strength, and intelligence as long as he is touching it.
Kelly makes his way back to the slavers, and using the Eye of Zoltec he manages to bring the criminals to justice and set the other slaves free.
Tim Kelly's is the star of Kelly's Eye. Originally created for the anthology comic Knockout, Kelly's Eye transferred to Valiant when Knockout was cancelled and merged with it.
Whilst in contact with the Eye of Zoltek Tim Kelly is completely impervious to harm, he cannot be blown up, set on fire, melted with acid, crushed with rocks, or cut with any sharp object (it will just break as soon as it comes into contact with him). Tim Kelly doesn't need to breath and is unaffected by extreme pressures and temperature, as such he can survive in the vacuum of space or the depths of the sea.
On top of the invulnerability, the Eye of Zoltek increases all of it's holders physical features, instilling tremendous speed, increased strength, and higher level intelligence and senses.
Tim Kelly has been shown running at over 100 miles an hour through a forest, and has been described as moving "faster than the eye can see" on more than one occasion.
His increased intelligence has allowed him to learn a new language in hours just by listening to it being spoken, and gain technical mastery of airplanes and other vehicles in minutes. Everything he learns stays with him even if he breaks contact with the Eye of Zoltek at a later date.
A Tim Kelly analogue named Tom Rosetta appeared in Alan Moore's acclaimed Captain Britain story "Crooked World". Here the character was a hero of an alternate dimension Earth 238.
The hero's of Earth 238 had been previously destroyed by the Cybiote construction named The Fury which had been specifically built with this task in mind. The Fury managed to somehow bypass the magical capabilities of Tom Rosetta's version of the Eye of Zoltec, roasting him alive.