Collect the Shard of Kozak.
The demon leading the operation in Felsoul Hold is an eredar named Azoran. In order to get to him, we will need to open a portal to the Burning Legion command ship.
Azoran has a demon jailer in his service known as Kozak the Afflictor.
Kozak the Afflictor holds one of the key shards necessary to open a portal to the ship. He can be found in the prison quarters known as the Halls of the Eclipse in the lower portion of Felsoul Hold.
Slay Kozak and place his key shard next to the portal.
You will also receive: