I saved Hjarlmar before I saved the archer, so I came back to him later and saved him from the ice trolls. The quest got kind of bugged since it told me to 'cross the lake' and nothing happened at the destination, so I went straight to the giant. The archer was there, and it starts firing arrows while the endless loading screen is there. Also, if I do some evades I can 'survive' the fight, if I don't, the giant kills me after three hits - or at least, I think that's what happens since the controller vibrates and the light goes from yellow to red.