Belphemon Sleep Mode is a Demon Lord Digimon. It is said to be sealed in the deepest part of the Dark Area. As the strength it possesses is too immense, its data is said to have been put in a Sleep state by the Digital World's system, although the truth of the matter is unconfirmed. Because it has fallen into a deep sleep, it cannot unleash its own attacks, but it is able to inflict damage to Digimon just with its snores, and for that reason it will not be easy to attack Belphemon Sleep Mode in its sleep.
- Eternal Nightmare: Invokes a nightmare with its peaceful snoring. If you are suffering from a lack of sleep, this technique is encouraged as it promises an eternal slumber.
- Lampranthus: Casts black flames from the chains coiled around its body.
- Belphemon: Sleep Mode (ベルフェモン：スリープモード)
Official romanization given by the Digimon Reference Book and used in the franchise.