When he first appeared, Montoya initially came off more or less seemed just another petty crook looking for money, acting casual and occasionally joking with his partners. However, the brief glimpse into his personal life and his subsequent calling out of his own partner for refusing to tip a waitress quickly showed how likeable a guy he really was and turned him into an Ensemble Darkhorse.
Rotor probably got his establishment as a rough and cold-minded but extremely competent leader when he lead the initially assaults on the XERRD Fortress, considering he got to show off his talents rather nicely.
Cabin's introductory scene more or less established her as a realist, though she had a few later moments that showed off another side.
Pharisee arguably got his when we first met him, coldly looking over the case files of several controversial individuals and judging them each harshly. It certainly sets up several things, among them his brutal beat down of Montoya.
Unintentionally subverted with Trigger, whose introductory scenes attempted to establish him as a Badass and an expert in the Maelstrom, but only caused people to see him as a complete Jerkass and an idiot.
Sarah Bishop's rather violent No-Holds-Barred Beatdown of Rotor, not to mention bludgeoning Cabin in the face when she tried to break it up should give you a pretty good idea of her mental state by this point.