When you go to the end, place a Netherportal block with /setblock command and go in there. What happens if you not set your spawn point, you are in the gliched world but with y=36000, but when you set your respawnpoint, you basically are in the gliched world too.

The gliched world is like a normal world but you can not take any damage, place or destroy block. The world doen't render correctly if you go some chunks out the world don't load, except you use /tp. You cannot use /kill to kill yourself in survival, because you don't exist in the world. I tried to go in the nether and the end but you can't. The only thing you can do is to waterlog objects