This is incorrect. The quest, and therefor the reward, are determined before killing the boss and completing the quest. I had a quest for a heroic cache, completed the kill on LFR, and received a heroic cache. You -do not- get a cache equivalent to the difficulty in which you kill the boss.
Quest
The Nighthold: Elisande
A World of Warcraft quest in The Nighthold. Facts and objectives from the current retail game data.
The highest voted Wowhead comments for this page. They are community notes, not TheWoWDB comments.
You can complete the quest in LFR...you are welcome :-)
Quest facts
The client quest POI data records no map location for this quest, so no map is shown.
Check whether you have already completed this quest
in-game: /run print(C_QuestLog.IsQuestFlaggedCompleted(43920))
Requirements
Read from the Blizzard quest API.
Description
Long ago, Grand Magistrix Elisande opposed the Legion and defied Queen Azshara herself. Passing millennia have changed Elisande's mind, and turned her into an ally of the demons. The time has come to face her.
Getting there
Inside the raid: The Nighthold
The largest structure in the Broken Isles, and among the grandest in all of Azeroth, the Nighthold stands as a testament to the achievements of the nightborne civilization.
Bosses in the Adventure Guide, in order: Skorpyron, Chronomatic Anomaly, Trilliax, Spellblade Aluriel, Tichondrius, Krosus, High Botanist Tel'arn, Star Augur Etraeus, Grand Magistrix Elisande, Grand Magistrix Elisande, Gul'dan.
Entrance: Suramar at 44.2, 59.5.
Instance text, bosses and entrances are the client’s Adventure Guide data.
Community notes from Wowhead · 3 comments
Top 2 shown above · 1 more hereThe comments below were written by Wowhead users. They are community notes, not TheWoWDB comments. See them in context on Wowhead.
I noticed that it rewards a chest equal to the difficulty you completed the quest with.
you do it in LFR you get an LFR cache.