Campaign/oneshot im making

Hey guys princessprt here and I wanted to tell y'all about a campaign/oneshot I was working on. so players start out in this maze to enter a plane because this plane kidnaps people. So the players have to find out why. They hear about a horrible creature which has killed many. However to enter it's domain you must find out how it got there in the first place. The password hint being I am an omen. This refers the the beast's past who is named omen. No omen is not the password it's the beast's name not their past name. So players level up and find out the password and I hope they reach level 20 before they find out. Because entering Omen's plane is to understand that you are entering a plane that would consist of chaotic evil. Thing is tho that both planes are held together by Omen's sister who casted this spell on her to try and save her. Where the plane separates into two halves one half trying to help and the other half trying to protect. The side that protects believes killing omen is a bad idea and has become twisted trying to protect her. This side is the Demi plane. Both planes held together by the spirit of a choosen hero. The Demi plane is as chaotic and unfair as it gets. The plane's goal is to protect omen however this means dunegons that have come to be are like little safe Havens because omen doesn't go where she knows that traps are. If the players are made of anything but meat they are kinda safe so long as they don't interfere with omen and her hunting. There is currently only one way to escape and close both planes sending everyone back to when and where they belong. It is to kill omen. There are other ways but an idea is to have a npc party race off against the current party. The npc party's secert is that they are being tricked by the ancient evil that caused omen to become her undead self. The party should find this out before entering the place.So far we have the Darkest Oceans where a bunch of terrifying things lie in wait for careless adventures to wander for perhaps a meal. thats only 1/13 of the areas i have planned. Each Area sort of counts as a Different boss stage. So hope to run into a dunegon before your health drops to low. anyway i'll talk to ya'll later bye!