"Safeguarding" - Player A starts a fight with Player B, BUT Player B has bought protection from Player C, so Player A must first beat Player C before they can fight Player B.

I know this is more or less what "buying protection" is all about, but I think the above mechanism running through the game itself would make it funner or/and even better than just sending someone money/points/whatever for protection and they have to potentially die before they get "protected".