[@Sypherkhode822]

You actually need to ride through a desert on a horse with no name for 9 days, then once you release horse, the desert would turn into X's realm.

X's realm can actually be accessed through all the realms since it's planned to be the realm between the realms. Some sort of Patchy Nexus which touches all the realms due to its weird spatial geometry. I haven't quite decide on how to access the realm between realms since usually if you're making a portal from one plane to another you'd actually step through X's plane which lies on the edge of the portal... A such if you could extend your portal to widen the gap, then travel down the path until you reach the Nexus where the sand begins...