Return to Anchorite Obadei at the Temple of Telhamat in Hellfire Peninsula and inform him of Sedai's death.
With Sedai's death confirmed, you're left with the unpleasant task of returning to Obadei with the grim news.
You will also receive:
- 2,430 experience
- 15 60 (if completed at level 100)
- 25 reputation with Exodar