Thirding the, "how is my character different than me?" research, and also writing up a brief background that digs into a character's history, goals, motivations, and activities other than being a professional adventurer. I couldn't settle into Azeban's personality until doing those, which made it really difficult to interact with other characters in a consistent manner during my first couple events.
I basically took the most core and important parts of my personality/motivations (needs to be able to wisecrack, gives a @#%^ about other people's feelings, needs to avoid actions [rules loopholes, serious treasure skimming, etc.] that disrupt other people's fun and damage the growth of the player base) and threw all the rest of me out the window. Azeban moves differently and has a different physicality than Wendall. Azeban values different qualities in people than Wendall. His motivations are different; his thinking, judgement and decision-making process both more black-and-white and wierdly filtered through his personal biata code of ethics; his capacity for cruelness is much greater to those who have not earned a place in his mind as an equal (and pretty much all non-biata start out in the "lesser than me" category). Such a big difference means I usually have to spend time psyching myself up to become Azeban and to decompress afterwards... one of the reasons I built and started wearing the big armor was because it helps me stay in character.
You can make Bruisey as much or as little like Bryce as feels comfortable. There's no wrong way to sort out your character's personality and, like Sid said, those big moments where you realize an event changes, solidifies, or otherwise makes your character's personality grow are big deals.
