Darlon is a dwarf, and the chief law enforcement officer for the city.  Their are three peacekeeping groups in the story: castley security, the valley military, and the city police.  Darlon supervises the police force.

Dwarves and humans have the most similar cultures,  approaches to law enforcement and legal systems, and Davis wants as multicultural a leadership team as possible, so a human-friendly dwarf is a good choice.  

Dwarves favor craftsmanship, commerce and underground spaces, so Darlon, choosing to work in a human dominated city in a social enforcement position, definitely makes him unusual.  Darlon is, by dwarf standards, a "people person" and detective, where the standard dwarf approach is how to understand how people tick so you can get a good contract, and good deal, Darlon likes to know how people tick in general.  The same feeling that most dwarves feel when they close a good deal, Darlon feels when he figures someone out, and solves a mystery.

In this way, he can have Dwarvish tendencies, but open to a deeper interpretation, and a slight outcast.

For most dwarves, Darlon's choice of vocations is odd, to say the least.  Dwarves do have some law enforcement, but most rules are enforced by clan, so the police role is very low status, very limited.

Darlon is from a low status clan, and rather than marry up, the traditional route, joined the very limited civil service, in the role of ombudsman, someone who specialized in resolving conflicts and disagreemes between clans.  His speciality was investigating "mysteries" unclear situations where the truth was hidden.  This was as close as elvish society had to a police detective, since the emphasis is on keeping peace between clans and fiscal prosperity for all, rather than human concepts of justice.

During the war, Darlon was intrigued by the possibilities around learning more about other races, and offered to act as intermediary with the humans.  Davis was impressed by his interest in cross species, and his keen understanding of behavior.  He helped solve a number of war time crimes, and became Davis's natural choice as chief constable.  

He is in the very unique and challenging position of keeping the peace in a unique multiculural setting, resolving strange and unprecedented settings.  He is, as are most dwarves, very cynical, and rarely thinks much about the big picture of DH, and tends to focus on his specific role of keeping the peace.  He also assumes that everyone is dishones and devious, which is a premise for most of dwarf society, which is fundamentally suspicious, expecting others to try and pull a fast one on them in any deal.  This is actually a fairly healthy  attitude for a police chief!

He is also impecabbly honest, following rules and honoring agreements.  This is a hallmark of dwarvish deals; you try to get the best contract you can, but once you have a contract, you follow it.  This was just reinforced by his experience as ombudsman, where he was expected to enforce agreements without prejudice.  He applies this to his law enforcement, setting high ethical standards and enforcing the law as it is written.  This will create challenges as the ambiguities of DH law develop.

He is, however, totally loyal to Davis, and fascinated and entertained by Davis's dreams about a better society.

Role:  Chief constable

Story Activities:  Darlon's role will evolve over time.  In the beginning, DH city is dominated by humans and orcs, who will have refugees looking for a new place to settle.  During this phase his status as dwarf, outside of both, is a plus, as they develop a system for resolving conflicts, defining laws, etc.

He will start with a small force, and the relationship between the three martial forces will be unclear; where does the military patrol have authority, and where do the police take over?  This relationship will develop over time, as the city becomes more developed, and it is clear Darlon handles urban issues, and the military handles castle and "rural" issues.

Perhaps unusual by human standards, dwarf ombudsmen are expected to be able to deal with the occasional physical conflict, able to break up fights, capture deal breakers, enforce agreements, etc.  So Dillan is a skilled and comfortable fighter, not the best of the best, but quite able to handle himself in most circumstances.

As the city becomes more diverse, it will actually be more awkward for him to deal with many of the dwarves, because by clan and profession, his status is rather low.  So Davis will back him up on that.