Marcen spent most of his formative years as a street urchin who learned how to take care of himself the hard way. He found early on that he had a knack for taking things from people without them being any wiser when the situation demanded it. He doesn't go out of his way to steal things, but if he sees something that he needs at the moment, he won't hesitate to find a way to get it or something similar that'll get the job done. He learned early in his life that the key to safety was to always have friends who were bigger, stronger or smarter than any enemies you made. And that once you had friends like that, to learn as much as you could from them.
Marcen is fairly non-descript, his most notable feature being a lack of any notable features. This allows him to blend into the crowd easily when he needs to. He's of average build but anyone seeing him in action would note that he has a lot more strength than you'd expect looking at him.