Thank you always, to Corey, from New Warriors Continuity Conundrum, and knowing when all these characters appeared! So, in Night Thrasher (V2) #2, the character, Chagrin first appeared, imitating Silhouette (as hired by Midnight’s Fire to do). Night Thrasher and Silhouette eventually track her down and defeat her and learn that Midnight’s Fire is behind it all.
I wish Chagrin would have appeared more after this. I am a sucker for untouched/undeveloped characters, and just wanting to know their backstory or create one of my own. She seems like someone who could have kept popping up in the Night Thrasher series, or even the New Warriors series, from time to time.
In the meantime, you can read the recap of the issue or check out Chagrin’s profile, all linked in that first paragraph.