First: cool idea. Me like. I think you could do a lot with it. That said…the best part of the piece was actually the blurb in the email, describing the idea. In other words, it needs more development.
About the character, I wouldn't call him "dead". A better adjective is "empty". He's a shell, a blurred simulacrum playing at being human. My feeling is that nothing he does is important to him. He might die tomorrow, but, like, whatever. He's homeless and starving and reduced to stealing his sustenance at great personal risk, and is completely nonchalant about it. The scene of him stealing didn't feel tense because it had the air of nothing important. I mean, here you have a desperate struggle to survive, with death by starvation on one hand and punitive mutilation on the other. Those are high stakes! But we don't feel that way because Marz doesn't.
How can you fix this? Well, I would start with defining your character. Give him an age, at least three quirks of personality, and a definite origin. Even if you don't spell that out in the story, you should know it so you know who he is. Give him a few goals, a few things that really matter to him. When writing his viewpoint, ask yourself how Marz would feel about where he is and what he's doing. Try to get into his character, with his voice. Don't go wild with the voice, since you'd have to be a master to successfully pull of any great variation from your own style (I know I certainly can't); just try to make it recognizably feel like Marz.
For a few ideas on how to develop a character like this, I'd read examples of what others have done. The two I'd suggest you read (if you haven't already) are Vin's viewpoints at the beginning of Mistborn 1 and the
first five chapters of Ender's Shadow (which are conveniently available on the author's web site). I found those two street urchin stories quite compelling. Look for the qualities that make them compelling, then emulate them. Remember: great artists steal.
Next up, I flinched at the inclusion of the "encounter with a mysterious stranger" trope. I feel like too many stories start that way, especially in fantasy.
Also, it looks like you're making up your own calendar. That's logical, since the Gregorian calendar is an (unfortunate) artifact of our own history. Might I suggest, then, that you avoid naming your months after the Gregorian's months? Especially Marz, which not only sounds like a leetiiied spelling of March, but is very similar to the Spanish word for March (marzo). It makes you look lazy, as in, "Oh, I need a new fake calendar. I'll make it exactly the same as the Gregorian calendar…and the months even sound the same…hmm."
In summary: cool idea, now develop it, develop it, develop it, develop it! (Picture a sweaty Steve Ballmer
shaking his fist at you.)