XIX. Boss Battle - Barbarian King
Once you've gone through the opening Quicktime sequence, you'll be given all your health back, so don't worry about that. Now you're facing off against a massive man on a horse. At the start, it's tough to get up close and personal with him, so use your bow until you're given the chance to slice up his horse.
During the second phase of the fight, he'll start to resurrect long-dead barbarians. Use your Circle attack to kill them in one blow and recharge your magic. Keep firing your bow at the Barbarian until he weakens.
Now it's the final section. Use your Rage attack to inflict as much damage as you can, then plug away with the Blades and bow until you're given the chance to finish him off with a Quicktime sequence. You'll be rewarded with his Hammer as a usable weapon, and you can change between this and your blades at any time by pressing R2.
