In Assassin’s Creed Valhalla, the Daughters of Lerion are super powerful bosses. They also count as Mysteries. The Daughters of Lerion are cultists who take pleasure in death and decay. They are powerful witches with the ability to confuse and disorient the player.
Defeating them will allow you to unlock Thor's Helmet and its attached achievement or trophy, depending on the platform you are playing the game. Each daughter drops an item that is used later on in acquiring Thor’s Helmet.
The Daughters of Lerion were the daughters of the mythical Briton King Lerion. They are Goneril, Regan and Cordelia. Lenior is also known as King Leir in the pseudohistorical accounts of Geoffrey of Monmouth History of the Kings of Britain.
King Leir was supposed to have ended the male line of Brutus of Troy as he sired three daughters: Goneril, Regan, and Cordelia. As he was dying, he divided his kingdom among his daughters.
The story of King Leir was made famous further by Shakespeare adapting King Leir's story into a tragedy, King Lear.
The First Daughter of Lerion: Goneril
Goneril can be found in Spalda Fens in Grantebrdigescire. She is in a large arena in a decaying swamp in northeastern Grantebrdigescire. It is highly recommended that you are at least Power Level 90 before fighting her. She is a step up from any of the story bosses you have will have faced at that point, including the non-story bosses like the Zealots.
Goneril’s go-to moves are vanishing and duplicating. You will likely miss hitting her when you use your abilities. Instead, it is best to use your light attack after successfully dodging her attacks. Goneril will stagger if you are able to evade her powerful rune attacks. Use this downtime to attack her. A riskier method of fighting her is to parry her attacks. You can also land quick attacks this way.
Goneril attacks with twin blades and uses strong unblockable attacks. She dishes an obscene amount of damage relative to what you have faced so far at this point in the game. The general rule in fighting her is just to constantly move, evade, parry, or run away. You cannot brute force your way into her. Practice some patience.
Do not forget to configure your skills to augment what you have in your gear. Use skills like Brush with Death when there is an opening after you dodged her attacks. Heavy Dual Wiled is effective against Goneril when you combine it with longer reaching weapons and a shield for increased defense.
When you reduce her health to half, she will then unleash clouds of poisonous gas. There are areas around her that should not be affected by the poison clouds. Go to these areaa and hit her from there. Defeating her will net you Thor's Breeches and Goneril's Dagger.
The Second Daughter of Lerion: Regan
Regan resides in East Anglia. This location is far west from the Forward Camp and far east of the Elmenham town. You should find a pit of decay in this area.
You should fight her when you are at least Power Level 110. She fights like her sister, Goneril, with all the teleporting in and out of battle, and duplicating. You can use the Axe Throw ability on her as other charging or ranged abilities will definitely miss. Just like the Goneril fight, your best strategy is running and gunning. Constantly dodge her attacks and counter-attack with your light attacks when she staggers. Parrying also works well against her.
Note that she uses strong spinning strikes and an unblockable leaping two-handed strike. Just run away if she is about to perform these attacks. Aside from that, she has this afterimage that performs the same attacks belatedly. Be very careful in returning to the area where she just performed her attacks since the afterimage will do the same in a short while.
Remember to evade the attacks which animate Runic symbols as these are unblockable. When she kneels down, run away immediately, or prepare to dodge as she is preparing an unblockable charge attack. While parrying her is a great tactic, she can also parry you back.
When you are able to reduce her health to half, she will be desperate and use her fire attacks. Roll around and evade whatever she is throwing since it is impossible to prevent yourself from catching fire once you get hit. Be patient and evade her attacks and she should go down.
Defeating Regan will reward you with Thor's Battle Plate and Regan's Dagger.
The Third Daughter of Lerion: Cordelia
Cordelia is the third and last daughter that you can fight. She is also the most powerful daughter that you will have to face and one of the most powerful bosses you can fight in the game.
Cordelia is found in East Anglia at Berkelow Bog. This is in the southwest corner of East Anglia. Head west from Grantebridge to find an arena festering with decay. There are also strange ritual symbols all over the place.
You must be at least power level 160 to fight her. This will mean that you have mastered control of your character and are knowledgeable about how weapons and abilities work. Although she is Power Level 340, she can be defeated with a below 200 Power Level if you know how to use your character and take advantage of her weaknesses.
She fights just like her sisters: fast and quick, wielding dual swords, and dishes an obscene amount of unblockable damage. In order to fight her, you can use Brush with Death, Parry Damage, and Adrenaline Fiend. Last Chance Healing is also a great ability to help you survive this dogfight. Grit is also essential in your survival.
Cordelia loves to use heavy and unblockable attacks. This should be familiar to you by now. Apply what you used against Regan and you should win this fight. Cordelia also has leaping attacks that are unblockable. Afterimages and teleportation are in her arsenal too. One attack that you should definitely watch out for is Cordelia teleporting away and summoning 3 phantoms. These phantoms attack quickly and are unblockable. You have to shut her down before she can summon these phantoms. Use Harpoon Impalement to stop her from summoning.
Cordelia will also draw in more power once her health is reduced to half. Her powers are electricity, making the latter part of your fight much more difficult. Move around evading the random thunderbolts. Close the distance when she is out of her lightning phase and hit her. You may choose to use your bow and arrow or use Focus of the Normir.
Patience and practice should help you in defeating her. You are rewarded with Thor's Gauntlets and Cordelia's Dagger.
Claiming Thor's Helmet
Now that you have all the three daggers, you must go to the cave marked on the map below. Go to the end of the cave until you find a statue that looks like the Daughters of Lerion.
On the back of this statue, you'll find 3 slots. Insert there the daggers that you have picked up from defeating the daughters and the statue will move to reveal a hidden staircase that leads to a chest containing Thor's Helmet.