The Demon of Darkness is a Zamorakian demon who must be defeated in order to obtain a demon's heart for Kolodion's spell during The Mage Arena II miniquest. In order to summon it, players must use an enchanted symbol to locate it, similar to using an enchanted key or strange device. It is recommended to keep Protect from Magic active during the entire fight. Even though it is able to hit through it, the damage players take will be halved. If players are assigned a black demon for their Slayer assignment, wearing a slayer helmet (i) is recommended, as the player's attacks will be more accurate.