She also became a hypocrite post Changes, mostly manifested by what she told Harry as to why she wouldn't return the custodianship of the Swords back to Harry, claiming she had better judgement where the Swords were concerned, he couldn't be trusted etc. Then turned around and did everything a Sword custodian shouldn't do, breaking the rules that govern the use of a Holy Sword, and got a Holy Sword broken. As Michael pointed out at the end of Skin Game, she appointed herself,custodian, she wasn't appointed.
To be fair, that was true to her past characterization, though it had been a while since we had seen that side of her personality. We saw the same character traits come out after she lost her police position that she displayed in
Storm Front and
Fool Moon. Granted that was a long time ago, but the same traits are visible.
Karrin has many virtues, but she also has a strong desire for control. Not to dominate others so much (though that can be a side effect when it goes badly) but rather control over her own situation, over events she's part of. When focused properly it made her a better cop, when it was focused badly it caused her to display bad judgement. Her reaction to out of control tends to be anger and an attempt to force control. She also hates to admit, even (or esp.) to herself, that she's afraid. It's a linked trait.
When she first met Harry, and realized the reality of the supernatural, her reaction was different from Susan's, which was an interesting contrast. Susan was fascinated, it was a vast fascinating puzzle, an enigma for her reporter's instincts, and (on a deep level) a big game to her. Karrin is smarter (in a practical, street-smart way, I have no idea about their respective IQ test results) than Susan, though, and her first visceral reaction to the discovery of the reality of the supernatural world was fear. She was smart enough, she perceived it clearly enough, to be
afraid of it.
But Karrin was never good at admitting fear to others or herself, and she reacted to that fear by trying to control it, to apply her comfort belief (the law) to it, to treat it like a mundane criminal conspiracy or the like. This was dangerous self-deception, and it eventually cost Ron Carmichael his life.
The events of
Fool Moon sobered Karrin up a lot, and also forcibly humbled her. After that, she usually recognized that the supernatural was too powerful for her, she simply was not going to have full control. Occasionally she started to fall into that former pattern, but Harry could usually bring her to her senses by reminding her of the
loup garou. We saw variations on that happen (off the top of my head) in
Death Masks,
Blood Rites,
Proven Guilty, and
Small Favor. In each case she would start to slip back into old habits of thought, and either Harry would remind of the
loup garou or some other supernatural event would remind her of the power imbalance, and she would sober up.
But when Harry apparently died and she was no longer a cop and no longer had Harry there, her control issues flared up again and that old anger and arrogance (which is disguised fear) reappeared.
Not really, because supposedly and many people here have argued that the main attraction of Murphy was the fact that she was very vanilla human, a believable character. That's what she was basically until she got fired from the police force. She was a martial arts champ, fine with in the limits of what is humanly possible for her size etc., believable. That's what people loved about her, but as time went on her character became more wonder womanish with supposedly the wisdom of Solomon, there are other characters that fit that role better than she did.
Exactly
Another issue with bringing Karrin back is the Harry/Karrin romantic/sexual relationship.
Back in the early books, a Harry/Karrin pairing seemed totally natural to me. I would find myself thinking that she made way more sense for Harry than Susan did. Their worlds and lives intersected comfortably. That was also before we knew about Harry's lifespan.
To my mind, though, even by
Proven Guilty or
White Night, the idea of Harry/Karrin seemed less and less plausible and natural. Harry's life was changing, it was kind of like they'd missed their 'launch window'. Also, Karrin's reasons for rejecting a relationship with Harry, way back when, were by no means trivial or bad. Harry's lifespan makes anything other than a temporary fling with a normal woman a highly doubtful prospect. Once we knew about his lifespan, suddenly Elaine or Molly both seemed like more natural prospects than Karrin. Elaine and Molly also seemed more 'natural' fits with the world Harry was moving in and the changes he was undergoing. By the time of
Turn Coat, I had started sort of hearing that Taylor Swift song in my head when Molly was with Harry and he would be thinking about Karrin:
You Belong With Me. When Harry was with Elaine, that too seemed more 'natural' after a while.
If Karrin were to come back as a baseline mortal...all the same relationship issues suddenly reappear, too. If she comes back as something other than a baseline mortal, one of her main character distinctions has vanished. I'm not sure this problem has a solution.