I have always thought that adding more dimensions to the game of Minecraft would make more people want to play. My idea for a dimension is based off of the Greed god, Hades. As most people know, Hades is the king of the undead. If a dimension based off of the underworld in Greek Mythology was added, there are several things about it that would be complex. First thing would be to make the River Styx. As is known in Greek Mythology, the River Styx is located and if you bathe in the waters of River Styx you would become immortal. Achilles, another character from Greek mythology,bathed in the River Styx. If you plunge fully into the River Styx, you will be killed. All but Achilles's heel was plunged into the river. He was killed by a poisonous arrow directed by the god Apollo that hit him directly in the heel. But anyways, it would also be the first CPU-character interaction in the game. If you entered this dimension, you would spawn near Hades's throne room. Hades would be about twice the height of a your character with about double the health. If you chose to fight him, you would obtain his helm of darkness, If you chose to do his quests, you would obtain his sword, which would be a diamond sword enchanted with Knockback, Unbreaking, Sharpness, and Fire Aspect. Also among the Underworld, there would be ghosts, that are hostile mobs who only spawn in the Underworld. Hades Palace would be somewhat like a Nether fortress, constructed of a similar looking block. Hades would give you 4 or 5 quests to complete before you obtained his sword, but once you have obtained his sword, you can't kill him to get the Helm of Darkness. Also, there would need to be Hellhounds added, especially Cerberus, Hades three headed dog. The entire underworld would be made of a different block, and would have stalagtites hanging from the ceiling. This dimension would only be about 1 or 2 chunks, and would be surrounded by bedrock, so there was no way to go into the void.