How to reach East Wastes: Zeixshi-Kar's Awakening
Unless you have completed the Portal Attunement quest for the East Wastes: Zeixshi-Kar's Awakening you'll have to take the long route to this zone. There are two ways to get here which are both basically equal distance. The first is through the Guild Hall, purchase the stone to Iceclad Ocean and then run one zone over to East Wastes.
The second way here is by taking the Great Divide stone in Plane of Knowledge and traveling west through Great Divide to East Wastes. I personally like the Iceclad route more since Iceclad's zone line in East Wastes is closer to the Fear Stone that zones us into Zeixshi-Kar's version of East Wastes.
Whichever route you take once you arrive in Eastern Wastes you'll want to travel down to the bottom right of the map which is where the Fear Crystal is that'll zone you into the Rain of Fear version of this zone. If you need additional help location the Fear Crystal take a look below for a map and a picture of it.