The Traitorous Ally

Not to be confused with the Traitor, a betrayer of usually more than one person instead of just one.

The one who betrays their single friend, leader, sibling, or other close associate. Contrast to the Traitor who betrays multiple people at once like what the slidetext said. The Traitorous Ally parts ways with their former supporter for many reasons: the former did something to displease the Ally, they were too weak or strong for the Ally, or another miscellaneous reason that would make one friend want to separate themselves from the other. The Traitorous Ally, in their absence, might have gotten stronger to kill their former and needs to be stopped by the Hero and their own allies as the Traitorous Ally has likely become an antagonist.