Head back into the aviansie in the Eagle's Peak Mountain. They will tell you your soul is at risk after helping Azzanadra. Describe to RuneScape gold them the positioning of Jaldroacht Pyramid, and they'll issue orders to the Desert Eagle below them. Next, you'll be advised that Azzanadra must be intending to utilize the Vault of Souls into ressurect Zaros. Its place is unknown, but it will be at a cursed place.
You are told the place is also underwater. Head to the Ancient Cavern, and try to start the Mithril Doors. You're thrown backwards, and several spirits appear. Now, you should run. Proceed to the aviansie and they'll be at a loss for words. Proceed to the Oracle, and she'll shriek if she discovers you moved there. She will inform you only a legend who wielded an elemental power, and was the master of his mind and body, ever escaped by the vault of souls. Go back to the Ancient Cave and kill a Mithril Dragon.
He'll automatically discard some chewed bones. Burn them outside on a pyre ship. If nothing happens, talk to Otto Godblessed about it. He will indicate a potion to help. Create a break potion from spirit weed and snape grass. Use it on your pyre ship, light it, and also a spirit will appear and give you a secret. He will say you must also wield elemental ability and command both mind and body. Go to the elemental workshop to the area which has the zapper chair and across from it's a locked door with all the entire body rune symbol on buy RS gold it* Open it with your key and search some shelves to the book of the elemental spear.