Use Gorat's Imbued Blood on Gorat's corpse, then defeat Captain Elendilad.
Fortune is with us this day, <race>.
Gorat's blood was fresh enough for me to conduct a special ritual taught to me as a child.
Use this imbued blood on Gorat's corpse to summon forth his lingering spirit.
Do his final bidding, then report back here to Kadrak.
Spirits keep you safe, friend.