The Sentinel's Eternal Refuge is a new craft legendary gear in 7.2. Requires lvl101 and can be traded in game. Because the map of the broken coast is very small, so there is the big chance for the fight between alliance and horde. This is a good use for this kind of craft legendary gear.

The Sentinel's Eternal Refuge is made by the Leatherworking. The recipe can be bought and learned at the professional trainer. It needs Leatherworking 800. You need prepare 2 legendary items and some blood of Sargeras. Nethershard Essence can be exchanged by Nethershard or bought at an auction house with WoW Gold. But the Wisp-Touched Elderhide need to do some quests. You can get the quest from the Broken Shore.

In order to start the quest, you'll need to have the Nether Disruptor building active in the Broken Shore.

The Legend of the Elderhide asks you to go to Val'sharah and capture 3 Ancient Wisp.
Then you get to listen to a  Fashion History and a Philosophy of Style.
After this will give you 4 new quests:

Leather of the Ancients: Requires 100 Ancient Dreadleather, this item drops from creatures in Broken Shore when using Ancient Dreadleather Armor.

The Wisp and the Sea: Requires Oiled Handmaiden's Gloves from Wrath of Azshara in Mythic Eye of Azshara.

The Wisp and the Shadow: Requires Dyed Shroud of Xavius from Shade of Xavius in Mythic Darkheart Thicket.

The Wisp and the Nightmare: Requires Immaculate Spellsash from Xavius in Emerald Nightmare in any difficulty.

If you have all of these, you can craft The Sentinel's Eternal Refuge. You can choose to use by yourself or sell it at AH.
Are you worried about the first legendary gear? Collect WOW gold to buy one at AH, this is also a good choice.