Claire's Dream Home

Claire's Dreamworld is an internal sub-reality sculpted and given form through the Genesis Key,   her quasi-soul.    This sub-reality or pocket-dimension is accessed through use of Architect of Doors or other abilities that might be capable of accessing this.   

Each time the Dreamworld is entered it can be dramatically different based on Claire's intentions and desires.  She isn't directly in control over the way the dreamworld manifests to the last detail,  but it generates the relevant environment to suit her purpose.  This means that she can be almost just as surprised as anyone else to see what the dreamworld has in store for her.     
Though she can't guide the generation of the dreamworld her Arc of Genesis magic can freely alter the landscape,  each spell capable of creating or using up existing matter to form something else equal to the same general area or mass of the spell used. 

The dreamworld can be a blissful haven of rolling hills,  steamy rivers and pools,  and flowers abound,    or it can be a merciless gauntlet of challenges with rivers of lava or sheer ice slicks capable of putting anyone to the test but always open to retreat and ways to push forward.   No room or space within the Dreamworld can be totally enclosed or leave anyone entrapped by default.   The only way for the dreamworld environment to cause harm or trap anyone is if they succumb to traps or fail puzzles and the like.   There is no way for the dreamworld to directly cause harm without some failing of the would-be victims.    A stepping stone over a river of lava was an illusion,  and they should have taken the other one.   A tile was a pressure plate,     or a hall is full of sweeping blades moving in pattern.  

Likewise,  no matter what happens or what traps are faced the Dreamworld cannot completely trap or completely block a path to the exit (The entrance).