What did a Fel Reaver drop?
Lu Li didn't know. He hadn't killed a Fel Reaver before nor had he seen anyone do it. If you thought that killing a Fel Reaver would drop scrolls, then would be naïve.
He suspected that even if he brought ten elite groups, he wouldn't be able to overcome the extraordinary strength of the Burning Legion.
Across the Hellfire Peninsula were dozens of Fel Reavers. If these monsters were already able to kill them, then the Boss of the map would be too much to handle.
The Fel Reaver scroll had a low probability of being dropped by Mo'arg the Engineer. However, they first had to have the prerequisite quest active, which was something Hachi Chan was tasked with acquiring.
Most of the people in Ruling Sword's core Elite Group acquired the quest as directed by Lu Li.