1) He's in, he's kicking butt, and he's after you. In the midst of the battle, run up to him. But right as he draws up his mallet, run out fo range. As he drwa it back up, fierce attack and repeat. Eventually you'll wound him enough to cut to a cinema.

2) Avoid the Troll's chain he swings by sticking behind the pillars. Eventually they'll deteriate.

3) As he draws it back, strike. Depending on your character, you can fit in 1 or 3 projectiles. Be on the look out though, an orc will come around up top once in a while. But if your low on health, you can get a nice green potion from him.