Witherboss
Terrarian
You have to go through a certain thing to get there but, once you arrive it's a different feeling like an trip through history and time like an weird atmosphere where the music is almost silenced but you can faintly hear it. The bones of demi-gods/gods in the backround not an single on to be spotted but there is still creatures, but they've been mutated from the gods power when they died. They're not gods but they're incredibly strong and the trees are withered as well as the ground like grayish. And there is new ores, armor, etc in this realm but there is an way to summon an god in this realm through gathering the parts of Cthulhu. (And he is the reason why the realm looks so despaired and dark and once you kill him it'll revert back to normal and why all the gods are dead) and making him whole once again to fix what he done to this withered world, and thus making it the way it was before Cthulhu's chaos with-in that realm.