Mimic will have to use some of his more monstrous abilities in a dire situation
If you look at the abilities of a mimic
he could become a far more formidable combatant if he doesn't mind losing his goofy and harmless appearance.
Madeline closes her eyes when fighting because she dislikes the sight of violence or pain.
Madeline has monk levels
After all you won't expect a paladin to be able to do this