Nex

Nex (coming from the Infernal word for "murder" or "death") is a powerful Zarosian general. She is a Zaryte from the plane Freneskae and one of Zaros' most powerful weapons of war. She is located in the Ancient Prison, sealed away in the back of the God Wars Dungeon. With a combat level of 1001, she ranks amongst the most powerful monsters in Edgeville.

You can reach Nex by clicking on the Boss Teleports tab in your spellbook and selecting the Nex teleport. It will spawn you outside of Nex's lair in which you will then have to climb down a rock slide to be able to attack.