The Frenzied Flame is something many players might not come across in multiple playthroughs of Elden Ring. The Three Fingers whose embrace holds the frenzied (and the future Lord of Chaos) in its thrall is found deep, deep below Leyndell. Inheriting this heretical, destructive, maddening flame unlocks a new ending that plunges the world into an Age of Chaos.
It's also the only Elden Ring ending that locks you into a choice – other unlocked endings can be selected interchangably after beating the final boss, but if you inherit the Frenzied Flame you are doomed to destroy the world... well, that's not entirely true, but in order to undo the Frenzied Flame, you will have to complete a lengthy NPC questline and defeat one of Elden Ring's hardest bosses.
Step One: Start Millicent's Questline In The Church Of The Plague
Millicent is a red-haired NPC who players find for the first time in the Church of the Plague in Caelid. Gowry will hint at her location if you find him first, and after talking to Millicent return to Gowry, who will give you some more information on Millicent's condition send you to find an item that can help her overcome the Rot.
This item is the Unalloyed Gold Needle, the same item you will use much later on in the game to undo your choice to inherit the Frenzied Flame. For now, head towards the Swamp of Aeonia and search for a boss named Commander O'Neil.
Step Two: Beat Commander O'Neil, Get The Needle, And Cure Her Rot
Commander O'Neil is not a particularly tough boss fight, though you don't fight him one-on-one. He constantly summons mobs to shoot and chase his target, though the ability to ride Torrent makes this boss and his cronies much easier to overcome. Once downed, Commander O'Neil drops the Commander's Standard and the Unalloyed Gold Needle.
Return to Millicent and give her the needle to begin the process of curing her affliction (or at least treating it temporarily). After re-loading the area by resting at the Church of the Plague Site of Lost Grace Millicent will be standing up - exhaust her dialogue here, then re-load the area again and head towards Gowry's Shack to find Millicent alone.
Step Three: Progress Her Questline, And Defend Her At The Haligtree
After talking to Millicent in Gowry's Shack she can next be found at the Erdtree-Gazing Hill in the Altus Plateau. Talk to her here, then go to the Shaded Castle overworld dungeon to get the Valkyrie's Prosthesis. Return to Millicent, give her the Prosthesis, then go to the northeast corner of the Altus Plateau and defeat the Godskin Apostle in Windmill Village. Talk to her here, then go to the Mountaintops of Giants to find her again at the Ancient Snow Valley Ruins Site of Lost Grace. After talking to her here, and she will move to the Prayer Room Site of Lost Grace in the Haligtree.
Finish her dialogue here, then backtrack to the pest-ridden area before the Drainage Channel Site of Lost Grace to defeat an Ulcerated Tree Spirit. Two summon signs will appear in this out-of-the-way location - one to help Millicent and one to invade her. Help Millicent fend off her attackers, then re-load the area to find her sitting on the shore. She will give you the Unalloyed Gold Needle, which must be taken to Malenia's boss room far below.
Step Four: Use The Needle At Malenia's Flower, Then Fight The Dragonlord In Farum Azula
You must defeat Malenia to spawn a large lotus-like flower in her boss room, which is a task much easier said than done. Once she is downed, re-load the area and walk up to the large flower in the middle of the room. Use the Unalloyed Gold Needle on the flower to get Miquella's Needle, a single-use consumable item.
Head to Crumbling Farum Azula after getting Miquella's Needle and make your way down to the very bottom of the airborne ruins. It's a bit of a maze, but you'll know you're in the right place when a secret Boss Battle begins. After this boss is defeated, use Miquella's Needle on yourself within the boss arena and you will no longer be held in the thrall of the Three Fingers.
Elden Ring is available now for PC, PlayStation 4 and 5, and Xbox One and Series X|S.