New emptiness world is really cool!
It's not only chance to continue all thaumcraft bosses and dungeons. There comes some ideas. Ideas about this rift portal. It's like someone swiped by something sharp and made this rift.
What about to add something sharp(Sword, knife, scalpel, even scissors) that will tear world, making short-life rift? Than, when player enter rift, you can add teleport to emptyness or simple teleport. OR, you can add interesting effect after entering. Something like player became spectator and have choices where to teleport.
There many possibilities and ideas with rift system)