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In my Lusotannan campaign one of my puppet kings in Gallia got this sort of thing. When spawned (outside the settlement) he didn't get the client ruler trait and had full mp. Moved into the town, he got the interloper. To hell with it I said and decided to use him on field. But on his way to a fort he got the cr trait and diminished mp.

I had to locate him with the help of move_character.
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