Rush's role in Gambit is mostly professional. As Willow's sweeper and part of her security detail, he focuses the majority of his attention on his duties. In Mimic, he becomes more of a protector and friend. He's grown fond of her, and, because of her obvious vulnerability, tries to warn her away from the danger she has a funny way of attracting.
Gambit portrays Asp as a reckless, carefree individual who laughs in the face of danger. Diving headfirst into battle with a wink and a grin (and all the high-tech protective gear currency can buy), he's not overly worried about Willow's enemies. In Mimic, however, he ends up facing an enemy of his own—a particularly nasty one he's been after for years and who's always somehow managed to evade him.
Gambit didn't portray Thess in a positive light. Under the extreme circumstances, he really wasn't able to put his best foot forward. He doesn't seem to have changed much in Mimic, either, as his tendency to behave like his father makes him appear lofty and self-centered.
Blood connection is a priority to Fenn. He places a great deal of importance on the Roanoke name, and Gambit shows his sincere willingness to make Willow's transition into her new elite existence one of ease and luxury. That willingness doesn't abate in Mimic, even when her evolving skillset and unpredictable behavior put his diplomacy skills sorely to the test.
War changes people. When push comes to shove and sacrifices have to be made, a person's true character emerges. Gambit made it clear that Morry's greatest desire is for status. Not fully understanding her background, it would be easy to assume that her selfish ways make her more of an opponent than a mother. And in Mimic, she's still working things to her advantage. The icy layer around her heart has yet to be thawed.