The Spiritual Plane

"Realm of the spirits"

Not much is known about this plane of existance. It exists as a blanket over all of Ecquamas. And it is the home of Spirits and the hiding place of powerful beings like the Greater Demons. In this place these beings are able to properly control their immense power and Essence that they possess. Something that would be impossible in the Mortal one.
Matter doesn't seem to exist in the Spiritual Plane. And when you do enter this mysterious plane you do not do so physically, but isntead you do so mentally. Meaning that this realm cannot affect your body. Your mind however, that is a different story. Many people warn of the dangers that come when entering this place. The immense power of this place and the creatures that inhabit it can easily break you mentally or drain you of your Essence.
Even though this place can be very dangerous, many people still visit it to talk to their patrons such as the Tetrad. Or the other way around, where their patrons drag their followers into the Spiritual Plane to personally talk to them. This plane is as crucial as it is dangerous to these people. And they'd do well to respect it.

Mystery Realm
Even though a lot of people use this realm, nobody actually knows how it works. So little is know about it that people have spend their entire life's researching this place.

Sadly much of this research was lost during The Blood Wars, and people have lost interest in continuing this research. So for now, this realm will keep its mysteries.