The City(Upper-Realm) Edit
The City is practically a spot on Earth were all the Sky Kingdom-outcasts go when the get sick of Outcast island. If you want your character to go there, he or she must be in illusion form(Human Form). The reason you must have an illusion form is because, even though there are already monsters there, quite a few humans live in the city, unaware of the monsters.
The Under-Realm City(Under-Realm) Edit
This city is located just beneath the Upper-Realm. This is a place only monsters, demons, and other creatures go. When your character travels her, he or she does not have to be in Illusion form. This Under-realm is different from the Under-Realm in the Creepypasta World(there is no Creepypasta World on this wiki). The Under-Realm City is much more fun than the Upper-Realm City(here, you get to kill people).