Item from Deltarune by Toby Fox
The red heart in Kris's chest — the player's control interface, the game's central symbol, and the thing Kris rips out of themselves every time nobody's watching.
In Undertale, the SOUL was the player's connection to the protagonist — a game mechanic. In Deltarune, it's a plot point. Kris has a red SOUL but it is explicitly the player's SOUL, not theirs. The game makes this literal: at the end of every chapter, Kris tears it from their chest, throws it in a cage, and moves on their own. The SOUL is the player. The player is the SOUL. When Kris obeys your commands, it's because the SOUL compels them. When they resist — stumbling, hesitating, moving against the direction you push — that's Kris fighting the player's control. The entire game is a meditation on what it means to control a character who doesn't want to be controlled. The red heart in Kris's chest is the game's thesis rendered as an object: you are playing this game, but are you playing it right, and does the character you're controlling want you here?
A glowing red heart — the same iconic red SOUL from Undertale. It appears in combat as the player's avatar, in cutscenes as a physical object in Kris's chest, and in the game's most disturbing moments as a thing Kris tears out with their bare hands and throws in a birdcage. It pulses with light. It is warm. It is not Kris's.
Also known as: The SOUL, Red SOUL, The Heart