Energy Sphere

The Energy Sphere is the Knight's part of The Elemental Spheres Quest, to get access to it you'll need to use 20 Small Enchanted Amethyst on the Mysterious Machine located in one of the Ivory Towers. At entrance of that area, there is a teleporter, you will spawn on surface and there might be up to 3 Charged Energy Elemental near you location, as they spawn near it. The Energy Overlord can be spawned in the South part of the sphere.