The Demon God is one of the main characters of Just Kill Me. He is the most common enemy fought throughout the game.
He has a very basic appearance. He is completely white, and has a humanoid body with a head resembling a cat's with two pointy ears. He has a tiny face at the center of his head composed of two black dots for eyes and a mouth, which can be mistaken as his nostrils and mouth with him lacking eyes. Upon being killed, he lets out a loud meow before detonating.
He has a personality which could be described as capricious. Despite his name, he is not actually a malevolent character. He does not seem to mind that the player is seeking to destroy him and even helps the player in killing his copies during certain parts of the game. Throughout the game, The Demon God has conversations with the player, often speaking about philosophy. The Demon God has an intense grudge for the god Demiurge, whom he consistently refers to as "That Guy". He is revealed to be a rather deep individual, giving good life advice and speeches on the nature of the world.
Though initially presented as the god of demons, he is actually the ancient god of destruction, Destroyer. Billions of years before the events of the game, the Demiurge and Destroyer ruled over the universe, keeping things in balance. However, one day Destroyer erased the concept of "eternity", thereby creating death. This greatly enraged the Demiurge, who banished Destroyer to a dark realm. Eventually, the Demon God reveals that he actually created Humanity as a destructive force, and that the Demiurge hates humanity because of this.
In the end, the Demon God reveals that he preserved some eternity in his own body. As a plan, the Demon God manipulated the player's mind and feelings, using the player's guilt to indirectly order them to erase Troy from existence, which would allow the Demon God to wreak havoc and revenge on "That Guy".
- His favorite food is sushi in the English version, たまごかけごはん (raw egg on rice) in the Japanese version, 蛋炒飯 (house special fried rice) in the Chinese version, and 찌짐 (Korean pancake) in the Korean version.
- He seems to be at least somewhat based off of Koro-sensei from the anime Assassination Classroom, as he shares a similar simple appearance and personality.
- He can produce a cat's meow, but not from his mouth. He also stated that if he sees a rat, a competitive spirit comes out from the bottom of his body.