Limbo Town is where all players are transported the day before a scenario shift is about to occur, unlike Peach Garden, Limbo Towns are separate per faction and you can only interact with players who are from your faction. However if there is a weapon/gear/item you had held in the broker before the change you are given the chance to take it back with you to move to the next scenario from any of the Orderly NPCs in the area. If the next scenario is not ready and you decide to reincarnate ahead of time you will be stuck in the scenario choice screen till the new scenario eventually gets added.
While in Limbo Town you can chat with friends and use 2 emotes which are only active here /bakuchiku which sprays some fireworks along the ground and /praise.
When the next scenario is ready(read on the Aeria Games forum when it is up) you can reincarnate via your bed. If you are in a Guild and wish to stay with them do not reincarnate before your leader or you will be kicked(by the game) and have to wait a week to get back in. This form or reincarnating does not use a Reincarnation Orb if you have one.