1. create a new hardcore world.
2. open to LAN with cheats on
3. /gamerule naturalRegeneration false
4. /gamerule doDaylightCycle false
5. /time set 14000
6. /gamemode 0 (if not already in survival)
7. save and quit
8. play world
it will be permanently night, natural regeneration is off, one death the world is deleted! its a lot more intense then regular survival and hardcore. its a fun thing to do if your bored.