The Cosmoscape Chronicles
Country Concept 6
This country will be in a blasted desertland of volcanoes. It will be home to Rakshasa elites who are enslaving demons and devils in order to create and army and in order to search for and dig up the remains of the now lost ancient civilization of Mael Garath (the ancient evil Tiefling civilization) because they wish to learn the ancient tiefling secrets in order to further enslave demon-kind (who betrayed them in the ancient war against the good angels) and hopefully destroy them (but of course conquer Aerth as well).
They will be constantly searching for artifacts and rituals and spellbooks that relate to fel-rituals and the like. Several demon slaves will escape and make their way north to the northern coast of seath, where a great underwater rift in the ocean connecting to the sun (i.e. baator, i.e. the 9 hells) will have opened and created a strange demon-infested jungle in the otherwise icy glaciers of the north. they will be finding a way to access the rift and create a connection with the 9 hells in order bring their masters back onto Aerth.