Adam Sharp was a member of the United States Troops based in Iraq, during the last War. During a game of Poker, inside the heavily armoured car his squad based in, he left to use the toilet, only for the car to be destroyed by Rocket fire, and Sharp himself to be torn apart with automated gunfire. He was then beaten and shot by Iraqi soldier's and left for dead, until he was picked up by the US army, and subsequently, Checkmate.
He was picked to be part of an experimentation into creating an "All-Weather" Soldier, based on how badly he was damaged after his time in service. However, during the operation, whereby his severed spinal cord was reconnected and he was treated with tissues prepared for an "All-Weather" experiment, a secondary solution was spilled into his open back, which gave him new, unforeseen powers. Checkmate had been given a completely blank slate, his mind was wiped from the brain damage he suffered from the beating and severed spine, and his identity was classed as deceased.
Trained and was tested against a number of animals by Dr. Brenner, a Checkmate scientist, Adam willingly transformed himself into a version of whatever animal was attacking him. Taking on their traits, with twice the strength and ferocity of the original creature. He was introduced, officially, after a battery of tests to the Black King of the time, Taleb Beni Khalid as Chimera. It was discovered, during his training, that Adam suffers from Reactive Attachment Disorder, normally found in young children who are neglected, as a result of this he is unable to form relationships with people, possibly created from his extensive .
Fortunately, Brenner devised a device to control Chimera, after he lost control and attacked, not only his Checkmate trainer, but the Black King and Fire as well. Shortly after this, despite protestations from August General in Iron and Sasha Bordeaux, Taleb mobilised Chimera to take part in the control of a large beast, one of many that had arisen over the world, as part of nature snapping back against Over-fishing, deforestation and other Environmental factors.
The battle was fierce with Chimera eventually defeating the beast, at first by transforming into the Shaman who originally banished it into Ice, three thousand years ago, and then by transforming into the Beast itself.
After the initial success, Chimera was drafted in to battle another beast, this time a long side the Global Guardians, until the Beast was eventually defeated, again by Chimera taking on a form to defeat the creature, taking Manitcore's poison barbed tail, and throwing the creature into water, it's weakness.
Again, against a beast in Japan, Chimera managed to use the August General in Iron's mystical staff, in conjunction with his own power to dissipate a beast made from pollution, despite his own over-whelming injuries of being impaled on a massive spire.
Finally, Chimera faced his most powerful foe yet, a beast who has been known as every evil god over the last ten thousand years, who called himself Lucifer to Chimera. The battle was desperate, with the Global Guardian's and all of Checkmate working against it, until Chimera took on it's most powerful fear - to become the Angel Gabriel, and slay the beast with a burning sword.
After this, Adam returned to his normal size and shape, away from the Tabula Rasa form of Chimera, becoming Adam Sharp again, at which point he and his girlfriend were allowed a "break" on a tropical Island.
Adam shows remarkable Psycho empathic powers, able to correctly guess cards with 100% Accuracy, read emotions and act of thought processes as well as reach out to his girlfriend in her dreams. Having been able to read the greatest fears of anyone he meets, making him a
difficult foe to move against. Chimera also displays an unparalleled regenerative healing ability, coming from extensive Stem Cell treatments he underwent to become Checkmates ultimate agent; The Chimera. Sharp's main power is the ability to shape-shift to adapt to most situations, taking on his opponents traits and powers accordingly, or manifest as the opponents most powerful terror.
He could also assimilate the unique properties of magical regalia to increase his power and tap into powerful extranormal sources that are biblical in nature to bolster himself. Chimera's mood swings and powers are, or were controlled from a device disguised as a Cigarette packet.