Use to douse the summoning area in the back of the Maw of Neltharion. Once you get the attention of Rothin the Decaying, kill him, then return to at the front of the cave.
With the cult's ranks thinned and some of their power stripped, it's time to strike at the source of the corruption.
Rothin the Decaying is resurrecting black dragons as magmawyrms in the back of the cave. Go to the summoning chamber and cleanse the remaining bones in the only way that they will never be toyed with again... with flame.
Burning the bones will surely gain Rothin's attention, see to it that he is destroyed as well.
The magic in this vial should see the task done.
You are quite an effective tool, <class>. Your hand in this purging is quite appreciated.
The bones of my blood have been spared this filth. You have served me well, and as such, you shall be awarded appropriately.
Use Neltharion's Flame standing near Rothin, who is invulnerable to all damage until you do so.
- Rothin the Decaying yells: No... NO! What have you done?! So many ancient wyrms wasted... what magic could do this?
- Rothin the Decaying yells: Foolish errand <boy/girl>... you will die for interrupting my work!
- Rothin the Decaying yells: This is not the end... death only... strengthens...