Loyalty is an unknowable unit stat, affecting how likely a unit is to defect or double-deal when possible. Thinkamancy spells can modify Loyalty.
It is possible that Ownership is the same stat when applied to Stuff. Since Croakamancy is not applicable to units because they have life, a Croakamancer such as Lady Wanda may be the owner of all that she has uncroaked. This may be why Wanda was so shocked that Ossomer was able to Turn after being Decrypted.
It is possible that Loyalty takes a ding each time a unit is Turned. Since most units are croaked instead of turned, or only turned once, this isn't too bad; a unit like Wanda, who's belonged to at least four sides, might have abysmal Loyalty, though. This, in turn, could affect how easily or likely it would be to unit again in the future.