After reviewing prior accumulated data upon the primarch konrad kurze, as well as soul hunter....I have concluded the night haunter is alive.
My idea is simple, the assassination and killing of konrad was staged. M'Shen was killed some time before reaching konrad, Shaal by instruction of kurze was instructed to act as the assassin. Thus why shaal saw everything first hand as he was there, however shaal did not kill kurze, konrad simply gave to shaal the corona nox as proof to spread his death. Shaal then ran off with it while disguised as the assassin M'Shen, is then ambushed by eldar, and subsequently is trapped in a warp storm and sleeps for a century or two.
Why did konrad do this? For in essence konrad truly did die, he allowed the night haunter persona to consume him. Thus all his duties to the emperor and his imperium he severed, from the great crusade, to leading his legion, he abandoned it all not caring what was to become of it.
Konrad did die that night, metaphorically with the giving away of his corona nox, night haunter is the one who left that room that night.