Didn't see a thread up dedicated to the quest specifically (at least not via search engine) apologies if there's already one.
GUIDE HERE -
Step 1) Beat the Shattered Throne Dungeon (location and how to get to it is included in video)
Step 2) There is secret mission at four horn gulch in the tangled shore after you beat the dungeon.
Step 3) Once you beat that mission you get 3 tokens of bosses. One token for each of the bosses you just killed. they are hidden bosses in the dungeon. You must do Awoken Charge objectives in order to spawn each of them
Awoken charges unlock hidden bosses and killing them with the acquired tokens from the four horn gulch mission is what unlocks the Wish Ender Exotic once you get to the eido statute before the final boss of the dungeon.
Due to the several charges all throughout the mission i think it's better to show in video and voice on how to activate each boss rather than type it out because it will read confusing as hell but i will try for those that can't watch.
Awoken charge #1 - It is in the first room of the dungeon. Located at the top left of the map on "Tower of the deep" climb to the top of it (there are 2 levels) and you will find the awoken charge. Head directly opposite of the tower and you will see another roof/dome and there will be statues on top. Find the statue that has no orb in hand and that is where you put in the charge Putting in the charge will summon the minotaur boss. Kill it to get your first token completed.
Awoken charge #2 - It is in the descent area where you walk on beams and several ogres spawn to knock you off as well as rotating blights. Kill all the ogres then proceed to the far right of the room, the awoken charge will be behind a pillar. Take it to the center of the room in the far back to dunk it into another statue that's missing an orb. After that you can proceed there will not be a boss.
Awoken charge #3 is in the very next section (Thrallhalla) the charge is directly to the right from where you enter. You must make it to the end with the orb and then drop down to the next location, look to your right for another statue with no orb and dunk it in.
From there you will want to go directly straight and head inside the door, you will be locked in and adds will start to spawn. Kill them and then kill the captain boss that spawns for your 2nd completed token.
Awoken Charge #4 - This one is located inside the first boss fight of the dungeon itself (the ogre) What you need to do is initiate the damage phase as normal but when you do, a invisible minotaur spawns in, kill the minotaur and an arc charge will spawn. Take the arc charge to the left hand side of the room from where you entered and there will be a statue missing an orb. Dunk it in and this will spawn your final token boss (it's another ogre)
Kill both ogres and you are essentially done. Head to the Statue of Eido and she will give you the Wish Ender exotic!