The Shadow Realm is a world where the Shadow God lives. It is paralleled to our world and is Earth's twin, but with more horror than normal. This world is featured in the thirteenth game of the Dark Parables Series, Requiem for the Forgotten Shadow.
It is unknown how long the Shadow Realm has been around, but as it is Earth's twin, it has become paralleled to the planet as in Yin and Yang. However, unlike Earth, the Shadow Realm is cold and empty, being wrapped in darkness. It was the place where the Shadow God was born. When he saved Guida down on Earth, it was possible that the Shadow Realm became her home after the Shadow God took her in.