This quest begins immediately after Fire and Faith. Now that Eivor has saved Richardis and defeated Gozlin (again), it’s time to confront Charles.
How to Enter Charles’ Sanctum
When the quest begins, you’ll find yourself inside the villa at Amiens. Charles is locked in his underground sanctum, and you’ll need to find two keys in the villa to open the door to it.
Where to Find the Key of Devils
The Key of Devils can be found on the western side of the villa, ready to collect from a gruesome table with a corpse on it. All you need to do is walk on in and pick up the key. You can also collect some food here if you’re low on rations.
Where to Find the Key of Angels
The Key of Angels is a little harder to find, since you’ll need to find another regular key to access it first. To find the regular key, go to the second floor and look to the northwestern side of the villa. Here you’ll find a door that you can open, with a barricade blocking the way beyond it. Move the barricade forward as far as it will go, then shoot at the wooden planks blocking the way around you. You can now enter the room and take the key by destroying the pots on the table at the western side of the room.
Once you have this regular key (Altar Room Key), go to the southern side of the villa on the second floor and open the door to the altar room. You’ll find the Key of Angels on the altar itself, at the western end of the room. You can now use the Key of Devils and the Key of Angels to open the door to the sanctum on the first floor.
Boss Fight: King Charles the Fat
The fight with King Charles doesn’t play out like any regular boss fight. The aim is to weaken him to the point where you can decide whether to finish him off and kill him, or trap him to spare his life. To do this, you’ll first need to hit his weak points which are located on his head and his left leg. Once you’ve done this, you need to damage him in whatever way you can until his final defence bar (just above the health bar) is depleted. At this point, you can drag and throw Charles into a nearby brazier, thereby weakening him.
Charles is incredibly slow, but his attacks can be powerful. You’ll need to avoid his red rune aura attacks in particular, but this can be done easily given how slow he is. Once you successfully throw Charles into a brazier, a good chunk of his health will be depleted and the brazier will be destroyed. You’ll then need to hit his weak points on the head and left leg again before you can weaken him to the point where he can be thrown into another brazier.
You’ll need to throw Charles into a brazier at least three times before you can decide to trap him, as the room where you can trap him will be locked until then. After the second burning from a brazier, Charles will begin to throw rocks at the braziers to extinguish their fires. You can easily light them again with your torch, but you’ll need to make sure they’re lit before you throw Charles into them.
How to Spare or Kill King Charles
Once you’ve thrown Charles into a brazier 3 times, you’ll be able to raise the gate to the room where the tapestry of Richardis is located. Entering the room will provoke Charles to follow you there. Once he’s inside, deplete his last defence bar until he’s stunned, then run out of the room and use the lever to lower the gate. A cutscene will then follow with Richardis.
If you’d rather kill King Charles than spare him, you can simply throw him into a brazier for a fourth time. However, Richardis will not forgive you for this.
What Happens if You Kill King Charles?
Aside from the difference in the immediate fight with King Charles, whether or not you decide to kill him will have an impact on the ending of the main story. As previously noted, killing him will greatly upset Richardis, and she won’t forgive Eivor. However, if you told Count Odo that you would kill King Charles if you got the chance, you’ll find in the next quest that he is grateful that you followed through with your promise.
Ultimately, killing Charles results in effectively supporting Count Odo as the new king of Francia. If you spare Charles, this results in Eivor supporting Bernard as the new king, though he is not yet ready. Your decision should be based on who you trust more between Richardis / Bernard, and Count Odo.
Whatever you decide to do, once you’ve dealt with Charles the quest will end.