The Shadow
The Shadow is a realm of darkness and evil. It exists as a realm adjacent to Palboria with only a thin veil of existance bretween the two.
It is unclear how the Shadow came to be attached to Palboria. Some say it was brought about by one of the gods. One text even claims Seolous himself created the shadow as a place to put any evil gods or who ventured into Palboria from other realms or Old Ones who broke in from the Outside.
The barrier dividing the Shadow from the physical realm has only been opened twice - the first to allow the First Titan and his generals to flee from the War With The Gods. Their fate beyond the veil is unknown, with many texts suggesting the First Titan waits with the remains of his army until the power of the gods is too weak to defend Palboria from attack.
The second time the veil was broached, shadow fiends entered the physical realm, resulting in the fall of the second human empire.
