M'Gann M'Orzz (Miss Martian)
Fancast: Karen Gillan as a teenager.
If you watched the (stupidly canceled) Cartoon Network show or read the Young Justice comic books, you know there's so much more to M'Gann than her Martian origins. Her struggles with accepting herself as she is, fitting in with the team, and walking the line between justice and revenge would make an incredible and character-driven film. She makes mistakes and learns from them. She's a mentor to the younger teammates. She learns to trust in her own abilities while trusting the team to have her back. Sure, she fights big bads, but who hasn't experienced some of those same emotions? Talk about connecting with your audience.