Agram is the primary villain in all the major portrayals of the Magi-Nation franchise which began with a card game and includes a video game and TV series. He is notably the mastermind behind the appearance of Shadow Geysers, gates to the Core region of the Moonlands that allow for the Core's influence to spread to the other, previously peaceful areas. Despite being the final boss of the GBC game, Agram isn't necessarily considered to be the archenemy of the protagonist, Tony Jones, due to his late appearance, and the fact that Tony is more often opposed by Agram's second in command, Morag, who better fits this description.
Agram's goal is to exterminate all life in the world in which he lives, which is formally called the Moonlands, a world populated by humanlike people referred to as "magi" with the ability to summon and control somewhat animalian entities called Dream Creatures for use in battle, as well as for convenience. His reason for wanting to commit genocide on these people is because they possess this said ability, the "power of the magi," which he considers as "stolen" from his original race, the people from whom this power originated, known as the "Ancients."
Agram is always seen wearing a blindfold over his apparently blind eyes, which is reportedly worn as a penalty for "seeing the secrets of darkness," likely having to do with his deep affiliation with the power of the Core.
Agram was originally one of a civillization of Ancients, a powerful race living in a hidden city who possessed that "power of the magi," an ability that allows its users to summon entities of varying strength called Dream Creatures to do their bidding. When a wandering tribesman named Agadon discovered the City of the Ancients, he was gifted with this power by the city's inhabitants.
One of the Ancients, however, opposed the prospect of a mortal receiving this power, and in retaliation for the refusal of the others to listen to him, utilizing the power of the Core, a region of the Moonlands hidden away from the others that contained a dark influence and shadowlike Dream Creatures, he waged a war against Agadon's tribe in an effort to ensure that the power of the magi remained soley in the hands of the Ancient race. In the end, Agadon defeated Agram, sealing him in the Core permanently, but at the cost of his own life.
As time went on, the inhabitants of Magi-Nation, eventually came to be known as all being descendants of Agadon's tribe, and as a result of all of them possessing the "power of the magi," these people came to be known as magi.
Over time, a rift between the Core and the other Moonlands caused by an unknown source allowed Agram to escape the Core and resume his mission in eradicating the people of Agadon's tribe. However, since by then, the entire population of Magi-Nation had come to be known as magi, Agram was now resolved to execute every last one of the people who now walked the Moonlands, and he began to once again gather his army, which was composed of magi with an affinity for summoning and commanding Dream Creatures native to the Core region.
Unknowest to Agram, however, the rift that had allowed him to return to the other Moonlands was caused by the arrival of a human from another world entirely, Tony Jones, a teenager from the modern United States. Eventually, Tony Jones was taught the ways of the magi by the locals, and possessing a far greater affinity for the "power of the magi" than any of the Moonland's locals, he eventually fought back at Agram's army and defeated Agram in a Duel before returning to the world from which he had came, and Agram was once again sealed within the Core, and the Moonlands kept safe from his influence.