Bounty Hunter. Won't fight unless paid to, period.
Ceras doesn't fit into the 'jerk with a gun and power armor' archetype, nor the 'badass who refuses to back down' one. He's calm and collected, but refuses to fight when not being paid for it. He prefer nonlethal over lethal, and always carries out a contract, unless his employer reneged. He has no mercy or conscience for his targets, but again, avoids killing when possible and tries not to cause too many problems... unless told to. Most of his contracts, however, are within the law; there are those jobs that he refuses to take.
When between jobs, Ceras finds some kind of bar or pub to spend time in, making sure his equipment is in good condition, and getting better equipment if available. He occasionally helps to settle disputes. He stays out of politics and most social issues.
His armor, naturally. Made from nanomachines replicating several different metals and compounds, it can patch up minor injuries and repair minor damage to itself. The latter occurs at the cost of protection in other areas; heavy repairs require outside materials.
He carries a heavy-duty taser, powerful enough to generate a mild electro-magnetic pulse.
For longer ranges, he carries a rifle armed with special pellets designed to shut down the human senses, effectively rendering them incapacitated. It works on several other species as well; if it doesn't affect his target, Ceras isn't taking the job.
For lethal requirements, Ceras carries a long-range gauss energy file, and a bolt pistol (the latter of which fires .50 rounds). For close range, he has a six-inch knife, which can also generate a high-energy field to increase its cutting strength, even against energy defenses.
However, Ceras also has the natural ability to disrupt most standing magic. This might enable him to disrupt a magic shield, but not a fireball. It's not particularly powerful - strong magic will be able to resist it - but it does have its uses.
Ceras Aston was among the last few humans to be born on Earth, or at least, his version of it. He wasn't there long, though - he and his family left the planet within the week. Ceras's birth, as the third child of his parents, was illegal. He was therefore taken in by the within two months of his birth, and literally raised into their military. But he was only our when the government collapsed, so he hadn't gotten much training. Passed around the galaxy from family to sympathetic family, Ceras eventually became a bounty hunter almsot by default.
At thirty-two, Ceras is neither the best nor oldest bounty hunter, but he does have close to the most experience and money.