We were two going up against Yagluth. It was pre H&H so maybe something's changed, but we used fire potions, good food, not upgraded wolf armour and I think I used un-upgraded Frostner for best effect. My companion used mostly bow at start but entered melee later. I don't think arrows were all that effective.

We used cover from stone pillars, kited around, running while he used meteors and moved in quickly after to get a few hits on him. Rinse and repeat. We died a few times, but it wasn't much tougher than the previous bosses.