Without going into much spoilers, this final quest is now broken as of 1.1.3 (completed it a few days ago on another character during patch 1.1.2).
During the fight when he grabs you two things will now fail to happen, you'll either get dropped (often to your death) or the synergy ability to escape does not appear
These issues prevent completion of the quest and progression into veteran content.
[Edit: Oops, this should be in either PVE or Customer Support forum]
Edited by Lunaris_Tenebrae on June 3, 2014 7:35PM