The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
Chabal2
Since: Jan, 2010
Jesthor
Since: May, 2013

Is there a trope for when you think the player character is good, but they are Evil All Along? By this, I mean where the player believes the PC is a good guy, but the ending reveals that all of your "decisions" have been working towards an evil goal.
Spoiler: An example of this is seen in "The Witch's House" (the true ending). The PC is Viola, who you lead through an evil witch's house. In the short ending, Viola escaped the house being tailed by the bloody mangled witch, but her father shows up and blasts the witch away with his shotgun. The true ending reveals that the witch switched bodies with Viola some time before the game started.
Does this make enough sense?