The quest appears fundamentally bugged: When searching for the 'Soultaker Dagger' in 'Near Infinity' it shows me it being present at the mirror-room, the lowest level of the Mad Dwarf's keep, Durlag. I have visited that room after already having slain the demon and the item did not appear to be there anywhere.
Therefore I spawned it in my inventory with EE-Keeper. When approaching 'Hurgan', he told me to recover the dagger quickly, which irritated me, since it already was spawned in my inventory. When I left the inn, a groupe of cultists attacked me.
'Hurgan' acknowledged at least that one event and sent me to recover it once more, this time from the cultists next door, where the item again did not spawn.
Therefore I spawned it once more in my inventory with EE-Keeper. When approaching 'Hurgan' with it this time, he again keeps telling me to recover it quickly, just this time from the cultists, which I did?TL;DR: I'm playing on v2.5.10 and got the console up and running. I just want to find out how to finish these quests via it?