The eldritch nightmare staff is a staff that is created by attaching an eldritch orb to the Nightmare staff. Requiring level 75 Magic and 50 Hitpoints to wield, it can autocast offensive standard spells as well as Ancient Magicks. The upgraded staff is untradeable, but it can be reverted to its tradeable components at any time. If lost on death in the Wilderness, the killer will receive the staff and the orb.
A player performing the eldritch nightmare staff's special attack, Invocate
The eldritch nightmare staff has a special attack, Invocate, that consumes 75% of the player's special attack energy to hit the target for a high amount of damage, and restores the caster's prayer points by 50% of the damage dealt. Invocate can boost the caster's prayer points above their prayer level (like the ancient mace), up to a maximum of 120. The special attack does not consume runes.
The base damage for Invocate is scaled based on the player's Magic level, ranging from 39 at level 75 to 50 at level 99, which can be increased with magic damage boosting items. At level 99, the maximum possible hit is 60, or 67 while on a slayer assignment.