GAIA: The Dark Realm

From the beginning there were two identical worlds, parallel dimensions you could say. One of which, is full of life and colours, in contrast the other is partially dead, full of negativity and darkness with some very unpleasant creatures roaming around. One day an entity, a sort of shadow from the negative world, decided that it was bored of only ruling over one world, and wanted to transcend to the next to consume it. The entity itself can't cross over all together, so over time it has slowly been trespassing and leaving shrines of his own with creatures guarding it, in order to hold back the light of that world from shutting him off to his dark realm. The mysterious shadow was gaining ground, before almost enveloping the whole world, the darkness reached a mythic land. The land of a dormant creature, which had been inactive for centuries. When the darkness got too close, the creature awakened, it was the embodiment of the earth itself and it knew exactly that something was wrong, and it had to do something to stop what was going on.