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.
Not much is known about Joshua in Gambit. As a guardian, he is a complete mystery to all who become entangled in his seemingly magical web of protection. Mimic reveals a bit more, but he is still very much steeped in shadow, his probablity vision playing a bigger role than his character.
Gambit threw a glaring spotlight on Reece's raw brutality. The rising conflict between his drive to succeed and his own desires nearly destroyed what he was trying to build. He shines softer in Mimic, stepping into the role of Willow's friend, confidant, and beyond. In spite of all he's done, he truly wants what's best for her. Even if she can't see it.