#1: 2;7,100x1,2,64x0,20,80x8;3;decoration,lava_lake,dungeon

Realm of Fright



ok, so for this first default, from top to bottom, there will be eighty layer of water, a layer of glass, 64 layers of air, then a layer of dirt, then stone down to bedrock. lava lakes, and dungeons will appear. the water at the top blocks sunlight, so mobs are always present.



#2: 2;7,100x1,2,64x0,20,80x8;14;decoration

Realm of Light

this one is incredibly similar to the first. a roof of glass, holding back a sky of magma. the surface is just the same, although it's a mushroom biome. note that in these defaults, you spawn on top of the glass. in Fright, you're underwater, so you can break the glass and swim to the surface. not so much here, so I recommend creative mode.