Dreamscape was a place that was neither real nor a part of the Dream Realm, but instead existed somewhere in between. It was created and maintained by a combination of advanced modern technology and a very special Aspect Ability that a certain Master — now already a Saint — possessed. Their power had to do with illusions, and so, that was what Dreamscape was.
A massive illusion that countless people could share.
However, that illusion was not entirely malleable, and functioned according to a set of absolute rules. It reflected reality instead of being a complete replacement for it. As the result, a person entering it was bound by the same laws that existed in the real world.