Walkthrough[]
Go west and enter Amethyn where you will fight a Splinter of Fate, a replica of you that uses either chakrams, Faeblades, or a Longsword. Loot the chest and go north to find another one in an alcove to the right. Fight another Splinter of Fate and dispel the chest as you move west. There are several items on the table as you turn the corner to fight another Splinter of Fate. Continue along the path and fight double Fates then open the two chests and continue north to another one. Enter the Throne Room to view a scene and square off against Tirnoch.
Tirnoch[]
Tirnoch will create Splinters of Fate from you: Slay them and use Reckoning when ever your bar is full. This will drop Tirnoch in front of you and allow you to damage her. You will transition to a new island every time you deal 1/3 of her life bar and after transitioning two, then three, Splinters of Fate will spawn at a time. Be sure to dodge Tirnoch's attacks as you fight off the Splinters, but it shouldn't be too difficult. You can speed this process up by using Fate Potions to fill your Fate Meter instead of waiting to kill the Splinters of Fate. Once you reduce Tirnoch's shown health to zero, press the button to use a special Fateshift channeled through the room's Prismere to win the fight.
Afterwards[]
Once Tirnoch dies, the game has ended or has it? There is still much to do in the world of Amalur and the main quest is just the tip of the iceberg. Alyn Shir saves you and you awake in Rathir where you will receive very little praise and recognition for your saving the Realm, having missed the parade, and you will also receive a room at the Orbocant in Rathir's Upper City).
One slightly interesting after effect of winning the game and then roaming around is that most enemies have respawned and some have gained a bit more health and defense to your attacks i.e it may take 3 hits, instead of one.
You are able to visit most locations though you are barred from returning to the Amethyn.