So your theory is not even close enough. Every demon in black clover ranked from weakest to strongest. Devil Black Clover Wiki Fandom Asta faces off against dante the demon king of spade. Black clover demon king . It is capable of stopping. 500 years ago lumiere defeated the demon created from the body of his brother becoming the first wizard king. Any objects in the area are slammed into the ground. Presence of the demon king juryoku maho mao no gozen is a gravity magic spell. With an open grimoire the user dramatically increases the strength of gravity in an area in front of them. Devils are generally large and humanoid in appearance with pointed teeth horns tails and bat like wings. Black clover demonsdevils explained duration. Every devil seen so far has access to particularly formidable and frightening forms of magic such as anti magic and kotodama magic. So that dosent mean that asta has a devil inside