The first boss of the Sunken Temple of Qarn (Hard) is the Damaged Adjudicator, ... The Damaged Adjudicator is separated into four parts, the Head, Arm, Tail, and main body.

Head through this door and jump up the boxes, and then go through this door here. Avoid the bullet bills in this area; if you get knocked down you’ll have to climb back up and try again.

The Sunken Temple of Qarn is an optional dungeon, unlocked by a side quest at level 35. ... Kill the head and the door will open. If the Qarn Facer is not defeated while on top of the panel, ...