Caelum/Proelium Dimension

Caelum is a mysterious ghost-like creature that is proposed to be related to Chrome and Nova. Caelum doesn't exist in the world and is only seen in brief glimpses, often surrounded by glitched squares and often ruins the environment around it. Ambience noises also signify Caelum being there.

Trivia

 * Caelum/Bullet Game is a secret boss in Bullet Game.