VIDEO UPDATE AND REFERENCE
Miles Edgeworth is a cold and calculating court prosecutor who makes it his personal mission to ensure every defendant he indicts is found guilty during a trial. While he would never go so far as to falsify evidence he is not above using under-handed tactics to bait his opposition into looking foolish by allowing them to follow a line of thought (that he has already considered or examined) and soundly snapping it shut around them like a visceral trap.
As time goes on he is forced into circumstances that cause him re-evaluate his position as a prosecutor and his personal "mission" in the courtroom. He gradually comes to warm up to others considerably, but not so much that he loses what could only be described as a "detached" personality.
Like most interpretations of Edgeworth: I perceive him as having a slight English accent (not to the extent of sounding overly "posh"- just a tendency to pronounce vowels more muted/flatly) as well as a calm and calculated delivery on most of his lines that give him a slight air of sophistication, harsh indifference, and mild smugness.