The Pretty Slave Ending is an Ending in Prisoners of the Elder One. It occurs after examining the vanity in the Bedroom five times.
Erik sees a photo on the vanity, and he gets more and more jealous of her, until he applies cosmetics in an attempt to look more like her. While his frame gets a bit shorter, he still doesn't look identical to her, so The Elder One helps... for the price of Erik's soul. Erik, now Brittany, eagerly accepts, and lives the rest of her life as the Elder One's slave.