Go back to Big Bend (entrance at 58,-12,270) and fight Skalmos. He will be on the pier.
Once defeated speak to him (Bug* If you pull him off of the pier and kill him he will re-spawn another attackable version of him but you can still hail the NPC he turns into after death) and receive message to give Gisuka back at Temple of War.
Go To Deathknell Citadel (portal at ( 8, -20, 13 ) Copy/waypoint 8.12, -19.67, 13.15) to speak The Overlord in his office.