There are ways to make each encounter simpler. I'll let you discover how, but Gut gets murdered in one round while she is alone (and supposedly so are you). For Manthara it is beneficial to go through the dialogue with a toon that has sanctuary placed on them with everyone else outside of reach (one next to the drum - but not close enough to be shoved - and destroy it first opportunity) having sprung Razza helps here as well especially if you have no intent on keeping her alive. As noted, the hobgoblin should be left for last, because all the goblins become hostile inside and out when he dies. Go through his dialogue scene and come out in his favor in any manner. Then blow the whole damned room up. Just make sure to have the smoke powder set up to his left. Do not want him and his loot to fly into the chasm forever lost. The other methods are not wrong, but I do not want to babysit Halsin while he is in Bear form (in a Campaign I want him to live anyway) and I find the Ogres more useful in another fight and would rather them perish in it for 2 of my own reasons.
