The High Priestess

The High Priestess is a Expert Mode item that lets you leave and enter the Etherial at will. When being placed, it is required to be wired and can be activated to enter and leave the dimension, though you can also use it by hand. An odd amount of wires needed to be connected, or it will immediately switch back. Placing it down will not consume the item, and breaking the placed version will not drop anything.

It is dropped by Etheria with a 100% chance but only when defeating her in the Etherial Dimension on Expert Mode.

Tips

 * If you're trying to build something, this can be used because significantly less enemies spawn in the Etherial Dimension.