I still enjoy Anja as well, but very much agreed on how she was written.
A fair amount of her characterization could have been salvaged if the rest of her party actually came down on her super hard after she annihilated an entire country during her rampage. She knows she fucked up, but she never digs deeper than surface level of "oh no I did an oopsie." Combined with an absurd lack of consequences for her actions it becomes the most insane underselling of a cataclysmic event caused by an MC I've seen portrayed in quite some time.
How could this have been fixed? First off, Razmi is the ONLY character who stays behind after finding Ajna. Everyone else leaves either out of disgust, anger, disappointment, or are just needed elsewhere as a result of the fallout (checking in on family or something). Then as you recruit your former allies back into the party, one by one each of them takes the opportunity to give her the riot act and describe what her actions has personally cost them and/or their loved ones.
CONSEQUENCES for her actions so that not only does she know how badly she screwed up, but FEELS it. Hammer it into her so that she understands that she has to atone for the damage she has caused.
One of the worst conversations in the game is when Ajna encounters Mara's daughters only to casually blow off their legitimate grief over the death of their father with "oh yeah my dad died too, sucks huh? Nah I totally get why you're mad." BUT DO YOU THOUGH? CUZ YOU SURE DON'T SOUND LIKE IT! Imagine if that conversation had instead started with her acknowledging their loss and expressing a desire to do what she can to make things right. Perhaps even commenting how she now understands how Dhar must have felt after learning the truth about Revannavar. Finally she doesn't just feel bad about killing Dhar, but begins to have a deeper appreciation and understanding of who he was and why he did what he did.