[@Obscene Symphony]I'm not entirely sure what you mean by a guardian "losing" it's [s]human[/s] partner. Like did they just run away? Whatever the case, obviously don't live forever [s]and not to mention..."How did you lose your partner guardian??.... "Ummm, shit happens?" Lol[/s]. So the idea of a guardian having been with multiple partners would be totally plausible. Though i'm still having trouble figuring out how they would be punished by switching up the power, if that were even possible. In my head, if a guardian were to commit a terrible crime or something, they'd just be killed in the spirit realm or cast away with the evil spirits, unable to find a partner to soul link with again. Maybe I just have a cold heart xD

Hmmm.... The only thing i can think of, if they used to be healing my mind goes to something beautiful/ charming/ elegant/ etc. Maybe they commited an act that was the complete opposite of these things, but because it wasn't as serious or because of somebody they knew with more influence they were not killed or casted away for it? 

Other than that... Holy cow, you're really about to get deep into it lol