Quest Talk:Blackthorn's Revenge

this quest could be incorporated into the primary quest seeing that vengeance is accomplished while you're assisting Tordag.
--JaqlinLeFleur (talk) 23:49, 23 June 2014 (UTC)

Yes, but no. It is a completely separate quest. If you have not completed the earlier quest, the messenger does not even appear.

The basic problem is this entire quest line has been bugged since Update 13 and not fixed. Meaning, no one has been able to complete it and thereby update the Wiki.