Golan Heights tank unit. Broke loose during Arab Spring in an attempt to assassinate a Muslim Brotherhood politician and his entourage. Originally injured in a freak rocket attack in Haifa, covered in burns, very serious internal damage. Magog is mostly composed of transplants, with an exoskeleton composed of an experimental woven titanium mesh, with even harder plates implanted in non-jointed areas.
Magog was once a promising Mossad operative, though still reasonably young. He possessed an excellent talent for language, and was very adept at moving through circles where Israelis would usually not be tolerated. His skin was somewhat dark at one point, which made this an even simpler process. He generally was a one-man or small team recon man, prepping for assassinations of important targets, due to his ability to remain unnoticed.
Mordechai Rosenberg wasn't a family man. He tended to be a loner, generally weighed down by the pressures of his job, despite whatever excitement he may have gotten from it. He did love his work, and found it to be a necessary evil for the protection of Israel, where he was born and raised. He cared deeply about his country (and still does, to some extent), and saw Mossad's actions to be absolutely justified. He wasn't the type to question orders.
His life changed dramatically in Haifa, when he was on vacation. In the middle of a crowded marketplace, a man (who was never caught) fired a homemade rocket from a rooftop. Mordechai was in the wrong place at the wrong time. He woke up in the hospital, missing both legs from the knee down, 46% of his body covered in severe burns, including his face, along with multiple fractures. The doctors told him he was lucky to have survived, and he believed them until he saw what he looked like. It was a pivotal moment in his life. His perception of himself shot downhill dramatically, and despair began to set in. He'd never have a family. He'd never be able to go back to Mossad. His life was practically over, as far as he was concerned.
One night, he was transferred while under sedation. He doesn't know where he ended up, and even some of Mossad's higher-ranking officers wouldn't either. When he woke up, he was suddenly not even human. His burns were no longer visible. Neither was his own natural flesh. He was restrained for some time, but felt that he was able to move even the extremely thick restraints around his hands, although his legs were still (momentarily) gone. He never saw what he looked like, but he felt a power in his body that was absolutely not what it once had been.
When he woke up again, he was in a different room, chained to a wall this time. The wall was steel, and there was a small window across from him. He realized that he was standing, and looked down for the first time. Where his legs had once been, there were goat-like legs, with hooves at the ends. Rage flooded him instantly, and he snapped his bonds as though they were twine. He spent perhaps an entire day in that cell, smashing deep indentions into the wall, pacing back and forth, getting used to the way his body (which he found absolutely disgusting, what he could see and feel) worked, the way it moved. There was an extreme power in almost everything he did now, and he could almost smash the extremely thick door in with the horns on his head.
At one point, during one of these rampages (which made up the majority of his stay in this room), an electric jolt flooded his body, dropping him to the floor. He was surrounded by a handful of agents, who announced to him exactly what had happened, and what would happen from now on. Where he was once the subtle touch, now he was the clenched fist. Instead of deep undercover, he would be smashing tanks in Golan Heights. He resisted, but found that each of these men had a small remote that could put him back on the floor within seconds, though he noticed the shock originated from his head.
Magog, as he began to call himself (to him, Mordechai Rosenberg was not a fitting name for the body he inhabited) was deployed in Golan Heights, just as he was told. He patrolled the roads in the dark, along the border. He was given special clearance to cross it, destroying any artillery that was even remotely within the disputed territory. He was relatively unsupervised, but his only attempt at escape was short-lived. The same shock brought him down, leaving him in the inhospitable terrain completely incapacitated.
A Syrian tank made the mistake of crossing one of Magog's patrol routes one night. In the process of doing his job, ripping it to shreds from the bottom up, he decided to test something. Repeatedly, he smashed his impenetrable head against the armor plating of the tank, disorienting himself slightly with each blow, but damaging the tank even more. The crew had already fled by this point, screaming wildly about the 'demon' they'd just seen, but Magog wasn't interested in them. Until he was physically exhausted, he ravaged the heavy tank with his head and horns. After a moment's rest, he decided to test his theory. He crossed the border into Syria proper. A very dull throb buzzed in his forehead, but nothing else. It continued, but nothing further ever happened. He made it as far as Aleppo before heading back, where he was approached by several men, one of whom he recognized; it was an old friend that he was often partnered with. If it hadn't been for quick talking on his part, those men likely would have died, but they presented Magog with an interesting opportunity: freedom.
They were moles. Not necessarily double agents, but part of an agency apart from Mossad. A group with even less sympathy for who they hunted down, what they destroyed. It benefited them for Magog to be set loose, because Mossad's leaders who were responsible for his 'creation' would be discredited internally, likely reassigned. Magog's allegiances at this point were gone. He hated what Mossad had done to him, he hated Israel for having Mossad. He hated, in fact, everything and everyone.
Faced with the opportunity of freedom, suddenly, this man, perhaps better called a beast, maybe even the demon he called himself, could destroy as he pleased, could take out his vengeance as he saw fit. Were it not a plan, it would have made a horrible mistake. Magog is by no means stupid, but he is extremely durable. He's not invincible, Mossad hadn't been so foolish, but working on his own, unsupervised, he's become a destabilizing force of his own. He's now a one-man army with no mission but to cause absolute chaos for the people who made him what he is.