I wouldn't call Barbatos the exception, he got tamed by Zagan somewhat, but he is pretty much also a douchebag.
Give Chastille some credit. He did fight to the death with another sorcerer for her, after all. Archangel pussy got him acting unwise.
I wish this series had less conflict, or at least had a some more downtime. People are reading this series for the Elf/Wizard romance, but we spend chapter after chapter on fights with new side characters we’ve never met before.
Chill out, have a Hot Spring or Vacation arc after all that fighting.
Honestly that's a problem I have with it, and it's less because there's dragged-out fights, but more because, why bother with the fights if they're over the moment the MC shows up? Zagan and Nephy both are stupid overpowered, and hell, Barbatos just lost a goddamn arm and it got better because reasons. Like, shit, let your characters have consequences and shit. An artificial arm could have been a great like, bonding point between Barbatos and Chastille, with him having lost it to protect her, and her feeling guilty over it. Don't just sweep it under the damn rug...
If you haven't read the spinoff, it's a good time. Less fights, a lot more underhanded-type conflicts and political conflict interspersed with Barbatos and Chastille bonding while Rachel bleeds out in the corner.