Hello, my name is Peni and I'm a drama queen.
It is true that intense identification with characters can disrupt the game even with that. We're on extended hiatus from one long-running campaign because my priestess walked away. I couldn't stop her. She was a perfectionist, a snob, and a deeply committed team leader (I made it clear to the others that I personally didn't think she was the leader, but Sofia assumed that her social class and relationship to our patron automatically made her that) who freely delegated responsibility in order to get the best results. She was fanatical about keeping "her people" alive and thought they respected her in her own right, as priestess, and as the patron's representative. When we got an adventure hook that was planted through her as priestess instead of through the patron, she asked for volunteers and - I thought - made it clear that this was *her* mission for the church and that how things were done was every bit as important as what things were done.
I have no idea, and in retrospect he doesn't either, why my husband's half-elf ranger chose this time to make his control issues with her authority overt. He'd always had them and Sofia'd always been oblivious to them, and in its own weird way it worked. He'd always been the go-to guy for tactics and she'd always respected that. But for some reason, this mission, the one she considered to be personally hers, was different for him and he didn't stay out of it and wouldn't be subtle. He started openly doing things he knew she wouldn't approve, changing plans without warning, and ignoring what she said. Twice he forged ahead into melee when she called for retreat or ranged combat, twice everybody else in the party followed him in preference to her, and both times she was bloodily and spectacularly proved correct and had to extend heroic efforts to keep everybody alive. One of those times, this involved Raising Dead on him. And then, when things were about to be wrapped up, he went behind her back, with the help of another party member, and made a deal without consulting her.
So she quit. Who wouldn't? The magnitude of the disillusion and humiliation she felt still makes me sick to my stomach. I told people I'd make another character and Sofia could retire to her villa, but - here's the weird part - nobody wanted that. They wanted Sofia back. People came to me in character and tried to talk her out of it. Even the offending half-elf realized, eventually, that he'd been in the wrong, and my husband wrote an in-character letter of formal apology that makes it possible for the game to resume at some point with the same characters. But they'll never be in the same relationship again, because something broke in the team on that mission and no apology will ever put things back the way they were.
So now the ball's in my court and I need to bluebook something that will make it possible to figure out how to get the old gang back together on a new footing, but one way and another I haven't been able to put the creative energy into it that it would require. Sofia is not an easy play. She used to leave me with a big knot at the nape of my neck because she was so tense. She'll have to mellow a lot before I'm ready to get back into her prissy head.