TheWoWDBHeads Up!
I'm not sure if this is the correct NPC, but inside the Dark Pens in Val'Sharah there is a room with a gate containing this NPC's corpse.
If you follow someone in, you can't get out! There's no lever or anything.
I was only able to escape via a friend with a Pineapple Lounge Cushion placed outside of the bars.
Elite
Cassiel Nightthorn
Illidari
The highest voted Wowhead comments for this page. They are community notes, not TheWoWDB comments.
Details
This roster comes from the current game client's data files, so it is not a complete list of every NPC in the game - older world NPCs that are no longer in the modern client are absent.
Community notes from Wowhead · 2 comments
Top 1 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.
not sure what you were doing in there without the quest line. If you follow the quests to this guy you have a key.
Level and Map Tracking
The game data tunes Cassiel Nightthorn for levels 8 to 45, Legion content.