A Shady Place

If you want to get [item=186191] do NOT deliver this quest before getting [item=186190] from [npc=179030]. [object=368653] is in a cave in normal phase but [item=186190] needed to open it drops from [npc=179030] witch is only visible when you are in the rift phase. If you deliver A Shady Place [item=187012] will disappear from your inventory and there is no way to get another one.
/way 23,8, 40,5 Elusive Keybinder Rift Phase
/way 21,1, 38,9 Etherwyrm Cage Cave Entrance (Normal Phase)
/way 23,2, 42,4 Etherwyrm Cage (Normal Phase)

[npc=179030] other possible coordinates provided from wowhead:

Spoiler

/way #1543 19.2 33.8 Elusive Keybinder
/way #1543 19.4 32.8 Elusive Keybinder
/way #1543 19.8 32.4 Elusive Keybinder
/way #1543 20.0 32.8 Elusive Keybinder
/way #1543 22.4 41.8 Elusive Keybinder
/way #1543 23.2 40.6 Elusive Keybinder
/way #1543 23.4 40.4 Elusive Keybinder
/way #1543 23.6 39.0 Elusive Keybinder
/way #1543 23.6 40.4 Elusive Keybinder

To free the Riftbound Vorkai, you need to use the quest item to phase into the shadow world, then free them there.

When you are done, phase back to the regular world and go collect each of them.

To be able to do the quest, you get a [item=187012] which lets you transition to the rift phase of the maw for an unlimited amount of time.

On live servers you are not able to exploit this to e.g. either find secrets in Korthia's rift phase or to kill [npc=179735] for the secret mount [item=186713] because you will get phased out of the rift once you leave the zone near the Ardenweald assault.