This quest begins immediately after The Wages of War. The Seed is dead, and the last link in the chain of command of the Children of Danu is Abbot Eogan. He is well protected at Armagh, so you’ll be launching an attack alongside King Flann and Sichfrith.
To begin the assault you’ll need to speak with King Flann in his tent, at the military camp established just northwest of Armagh. A cutscene will play once you enter the tent, and soon after you’ll have the option to begin the assault when you speak with King Flann again.
Assault on Armagh
Clear the First Courtyard
When the battle begins, you’ll find yourself just outside the main gates with King Flann and Sichfrith. The gates will open and you’ll be met by a number of regular units alongside a Wolfhound Master and an Irish Wolfhound. These are likely to be the most dangerous enemies that you encounter during the assault, so you might as well use whatever high damage abilities you have available to take them down quickly. If you get caught between the master and his hound, you’ll find that they can inflict a great deal of damage in a short amount of time, so it’s worth getting them out of the picture as soon as possible.
Once you’ve killed the Wolfhound Master and the Irish Wolfhound, you’ll have a number of regular melee and ranged units to deal with before the first courtyard is cleared. The most deadly of the melee units wields a two-handed hammer which can be highly damaging if you get hit, so focus on taking them out first. King Flann is an effective fighter, so you won’t need to worry about him dealing with the melee units as you make your way to the ramparts to deal with the archers. If you don’t deal with the archers quickly, they will continue to launch arrow volleys on your allies.
Raise the Portcullis and Burn the Village of Armagh
When you’ve cleared the first courtyard and the surrounding battlements of archers, you’ll be prompted to raise the Portcullis to the east. To reach the mechanism you can shoot the link on the ladder to the right of the gate, then climb the ladder to the top. Interact with the mechanism to raise the Portcullis and then make your way into the village with your allies. Once the Portcullis is raised you’ll note that the objective updates with a progress bar noting how much of the village remains to be burnt. You’ll need to throw torches on the top of the houses which are marked in teal (use Odin’s Sight to highlight them if necessary) until the progress bar is filled.
How to Open the Inner Gate
Once the village of Armagh is burning you’ll need to join King Flann at the inner gate to the southwest. To open the inner gate you’ll need to use the rope wire to the left of it, launching you to the top of the wall. You can then jump down and shoot the locks behind the gate to open it for your allies. At this point you’ll have to kill a few more enemies in the courtyard of the inner gate before you can make your way to the church with King Flann. Once you’re at the front door of the church, help King Flann to force it open and begin a cutscene.
Defeat Abbot Eogan
As you enter the church a cutscene will begin with Eogan, during which he attempts to turn King Flann against Ciara and asserts that the Children of Danu can’t be stopped. When the scene ends you’ll need to kill Eogan and the two guards. This will prove to be an easy task, especially with King Flann at your side. The only thing you’ll need to look out for is the disorienting dirt throw attack from Eogan, but even if you’re caught off guard and hit a few times, it won’t be enough to cause you any significant trouble. Eogan has no armor or other defences, so he’ll go down quickly and easily. A cutscene will play after his death, and the quest will end.