Well, those paralyze staffs will go to waste if we're already paralyzed by indecision, so we may as well take pity on Haspen and let him work his perfidy. :3
We have to keep on moving forward, and get out. Are we agreed that we should at least reduce the three in the room immediately? If so, then Tantallos can give the ring to Raquel for this turn; Derick moves up to (6,19) and holds; Raquel moves to (9,19) and zots the Sentinel - with the ring and vicious crit-rate courtesy of Derick and a doubling blow courtesy of the Tantallos' ring, which should guarantee a death as long as she connects. Gregor can move up and finish off the Bishop, then Edwin can move up and sleep the Sniper. If necessary, Olison can also move up and use the Short Spear to attack one or the other, though this is a bit of a desperation move for use if Gregor or Edwin don't connect. The rest should move forward and try to get out. No one else, unfortunately, is in a position to attack within the room; the nearest, Seyena, needs to move before we attack if we're to finish off the Sentinel and permit her entry. As far as I can tell, this appears to be the optimum course of action, as variants have been suggested by several people before me. Do we have consensus on this?
As for reinforcements, primary avenues of danger are the west and south - (1,22-24) and (10-12,30). We have been warned that paralyze stave wielders will be incoming, and we can also expect riders who will have superior movement. However, they'll appear one turn before they can move on the map, if Haspen continues to follow pre-Awakening rules on this, so we will have a turn's warning to set up a defensive line in order to optimize our strengths. What we absolutely do not want to do is get bogged down in the entry way; we cannot concentrate our fire the way they can with the walls in the way.