Guild Wars 2 – The Last of the Giant-Kings

Head back to the Osenfold Waypoint. Continue to the North and reach the Osenfold Shear. There you will find Eir Stegalkin with Garm waiting for you. Head over to the instance and begin the last part of this quest line.

Once inside the instance itself head over to the West and into the Shear.
Here, things vary some depending on how the previous quest.
Twilight of the Wolf:

Eir Stegalkin: “Wolf's blessing surrounds you like a moonlit cloud. I can see it, and so will Korag.”
Hero: “It will be the last thing he sees.”
Eir: “Indeed, but let's not kid ourselves: the jotun won't let us just walk up to Korag and start swinging.”
Hero: “The Dragon can cheat all it wants. Korag will die, and so will all of Jormag's minions.”
Eir: “Keep that confidence, Slayer. Doubt can cripple a hero, but a bold heart will carry you though when doubt grows strong. Go. Garm and I will be right behind you.”

Twilight of the Wolf: The hero is transformed into a wolf with the following abilities:
Bite: “Bite your victim with ghostly jaws.”
Range: 120
Lunge: “Lunge at your victim with a powerful attack
Range: 120, Cooldown: 5s
Leap: “Leap at your target.”
Range: 250, Cooldown: 10s
Baby Wolf: “Summon a spectral wolf to aide you in battle for a short time.”
Range: 500, Cooldown: 15s
Healing Howl: “Heal yourself through the power of your own howl.”
Range: 500, Cooldown: 20s

Out of the Skies:
Eir Stegalkin: “Here is the weapon Beigarth forges. So light, yet so resilient. A true masterwork. I can't wait to see it in action.”
Hero: “I've never seen its equal. If I close my eyes I can almost here the beat of griffon wings.”
Eir: “Korag will fall before you, but first we must cut through his servants. Garm has sensed corruption here. Be on your guard.”
Hero: “Korag will die. I'll deal the same punishment to all of Jormag's servants.”
Eir: “Keep that confidence, Slayer. Doubt can cripple a hero, but a bold heart will carry you though when doubt grows strong. Go. Garm and I will be right behind you.”

Windshear: “Swing your axe and launch a flying blade of wind at your foe.”
Range: 1,200
Griffon Strike: “Dart forward, strike your foe with a crippling blast of lighting, and then retreat.”
Range: 530, Damage: 164, Cripple: 3 seconds -50% Movement, Vigor: 4 seconds 100% Endurance Regeneration, Combo Finisher: Leap
Eye of the Storm: “Fling lots of lightning and thrash foe around you in a spinning frenzy.”
Range: 2,000, Cooldown: 10 seconds
Thundering Throw: “Throw a returning axe wreathed in lightning. Any targets hit by the axe  are struck by lightning.”
Damage: 232, Combo Finish: Physical Projectile, Range: 900, Cooldown: 20 seconds
Pack Hunter: “Summon Windshear's brood.”
Cooldown: 120 seconds, Range: 400

Head forward and you will first need to fight through 4 Jotun, all level 10. After that you have another 5 Jotun (Level 10) come at you. After that a set of 4 then 5 will come at you. This part varies based on what you have done. If you have received wolf's blessing then it is much more of a fight as you need to rip your way through the ranks of Jotun. If you have the Axe it is capable of tearing through each jotun in just a couple strikes.

Once you have waded through the rest of them Korag will appear and challenge you.

Korag
For a boss he is not the most intimidating thing. Focus on dodging his very obvious attacks. Call in aid when you can for this battle. With some movement to avoid his Elemental attacks and the few melee, it will be over before too long.

Once the fight is over the Hero will turn and address the surviving jotun. With some words from Eir Stegalkin that is all it takes to finish out this story line.