Lichdragon Fortissax is a legendary secret boss in Elden Ring, hidden within the deepest reaches of the Lands Between. Unlike regional bosses encountered during natural progression, Fortissax requires the completion of a multi-stage NPC questline involving Fia, the Deathbed Companion. Locating this four-winged black dragon is essential for players seeking the "Age of Duskborn" ending and the achievement associated with legend-type bosses. The encounter takes place within the Deathbed Dream, a unique sub-dimension accessed via the Prince of Death’s Throne in the Deeproot Depths.

Essential Prerequisites for Locating Fortissax

Finding Lichdragon Fortissax is impossible without first obtaining a key item known as the Cursemark of Death. This item is not found in the Deeproot Depths but is instead a reward for progressing through Ranni the Witch’s questline. Because these two questlines intersect, players must balance their exploration between Liurnia of the Lakes and the underground eternal cities.

Obtaining the Cursemark of Death

The path to the Cursemark begins by serving Ranni at Ranni's Rise. After defeating Starscourge Radahn, a meteor crater opens in Limgrave, providing access to Nokron, the Eternal City. Within Nokron, players must retrieve the Fingerslayer Blade from the chest beneath the massive skeletal statue in Night's Sacred Ground. Returning this blade to Ranni grants the Carian Inverted Statue.

With the Inverted Statue in hand, travel to the Carian Study Hall in East Liurnia. Place the statue on the pedestal at the entrance to flip the entire tower upside down. Navigating this inverted dungeon leads to the Divine Tower of Liurnia. At the summit of this tower lies the Cursemark of Death, carved into the flesh of Godwyn the Golden’s original body. This item is the catalyst required to advance Fia’s dialogue once you reach her final location.

How to Reach the Deeproot Depths

The physical location of the Lichdragon Fortissax encounter is the Deeproot Depths, an expansive underground cavern situated directly beneath the Royal Capital, Leyndell. There are two primary ways to reach this area, though the path through Nokron is the most common for those following the intended quest progression.

The Route via Siofra Aqueduct

After exploring the main areas of Nokron, head north toward the Siofra Aqueduct. This area culminates in a difficult boss fight against two Valiant Gargoyles. Upon their defeat, a stone coffin sits at the base of the waterfall at the back of the arena. Interacting with this coffin triggers a cinematic where the player is transported up the waterfall and deposited into the Deeproot Depths. This is the earliest point at which the location becomes accessible.

The Subterranean Shunning-Grounds Shortcut

Alternatively, players who have explored the sewers of Leyndell can find a hidden path. Behind the altar in the arena where Mohg, the Omen is fought, there is an illusory wall. Descending through the frenzied flame proscription leads to a secret entrance into the Deeproot Depths. This route is often more dangerous due to the platforming required but provides a direct link from the capital.

Navigating to the Prince of Death’s Throne

Once inside the Deeproot Depths, the journey to the Lichdragon Fortissax location requires navigating a vertical labyrinth of Erdtree roots. From the Great Waterfall Crest site of grace, head west across the sunken ruins. The goal is to reach the Nameless Eternal City, which lies further north.

To progress, locate the massive roots that climb toward the upper ceiling of the cavern. These roots act as bridges between the buildings and the cliffs. Follow the thickest roots upward, heading northeast. This path is guarded by several Lesser Fingercreepers and Basilisk enemies that inflict Death Blight. Eventually, the roots lead to a cliffside ledge featuring the "Across the Roots" site of grace.

Directly ahead of this site of grace is a large, open circular arena filled with shallow water and a massive, distorted corpse hanging from the ceiling. This is the Prince of Death's Throne, the final stage for Fia's quest and the entrance to the Fortissax boss fight.

Fia’s Champions and the Final Interaction

Upon entering the arena at the Prince of Death’s Throne, the player is not immediately greeted by the dragon. Instead, a wave-based boss fight against Fia’s Champions begins. This encounter involves fighting several NPC phantoms, including Rogier and Lionel the Lionhearted. These phantoms represent the warriors Fia has held throughout her journey.

After defeating the champions, Fia will appear sitting on a log near the massive corpse. To trigger the events leading to the Lichdragon Fortissax location, players must interact with her and choose the following options:

  1. "No, I want to be held." This allows Fia to provide her blessing and opens secret dialogue.
  2. "Talk in secret." Exhaust all dialogue until the option to give her the Cursemark of Death appears.
  3. Give the Cursemark of Death. Fia will express her gratitude and reveal her intention to conceive a child through the dead demigod.

At this point, the player must refresh the area. This can be done by resting at the nearby site of grace or fast-traveling away and returning. After the area reloads, Fia will be lying down next to the Prince of Death. Her character model will appear to be sleeping. Approaching her and selecting the prompt "Enter the Deathbed Dream" will teleport the player into the arena where Lichdragon Fortissax awaits.

Lichdragon Fortissax Combat Profile

Lichdragon Fortissax is a massive ancient dragon corrupted by the power of Death Blight. Understanding the boss's statistics is vital for survival, as this is a high-level encounter typically intended for characters between levels 80 and 100.

Health and Resistances

In a standard New Game cycle, Fortissax possesses approximately 12,903 HP. His defensive profile is heavily weighted toward elemental resistance, making certain builds significantly less effective:

  • Lightning Resistance: 80 (Extremely High)
  • Holy Resistance: 80 (Extremely High)
  • Magic/Fire Resistance: 40
  • Physical Resistance: 35 (Slash/Strike/Standard), 10 (Pierce)

Due to these numbers, Faith-based builds relying on Lightning or Holy damage will struggle immensely. Conversely, Dexterity or Strength builds utilizing Pierce damage (such as spears or heavy thrusting swords) will find the fight much more manageable. The head is the primary weak point, taking double damage compared to the body and legs.

Status Ailments and Immunities

Fortissax is immune to Sleep and Madness. He has high resistance to Poison, Scarlet Rot, Hemorrhage (Bleed), and Frostbite (starting at 552 resistance points). While status effects are viable, they require consistent aggression to trigger. The boss himself inflicts Death Blight via his black-gold lightning clouds, which can cause instant death if the status bar fills completely. Equipping the Prince of Death’s Pustule or using Rejuvenating Boluses is highly recommended to manage this threat.

Tactical Strategy for the Encounter

The arena within the Deathbed Dream is vast, but the dragon’s mobility and wide-reaching lightning attacks make the space feel small. Unlike the standard dragons of Limgrave or Liurnia, Fortissax utilizes red-gold Ancient Dragon Lightning, which has a distinct delay and high area-of-effect impact.

Phase 1: The Lightning Barrier

During the initial phase, Fortissax frequently uses a Lightning Barrier. Red lightning bolts will cling to the player’s body and explode after a short duration. To counter this, players must avoid staying under the dragon’s belly for too long. While attacking the legs is a common strategy for other dragons, Fortissax’s lightning discharge makes the head a safer and more rewarding target. Standing directly in front of his snout allows the player to bait out bite and claw attacks, which are easier to dodge and leave the head vulnerable for a counter-attack.

Phase 2: Death Lightning and Glaives

As the dragon’s health drops below 60%, he becomes more aggressive. He will begin using Fortissax's Lightning Spear, where he conjures two red lightning spears and slams them into the ground. The resulting shockwaves travel outward, requiring precise jump-timing or rolls to avoid.

His most dangerous move is the Death Lightning roar. When the dragon roars and the sky turns dark, multiple pillars of black lightning will strike the arena, leaving behind clouds of Death Blight. Players must immediately disengage and find a clear patch of ground. Staying inside these clouds for even a few seconds will result in an instant Game Over, regardless of the player's HP.

Rewards and the Mending Rune of the Death-Prince

Upon successfully defeating Lichdragon Fortissax, the player is returned to the physical world at the Prince of Death’s Throne. The dragon drops 90,000 Runes (scaling up to 344,250 in NG+7) and the Remembrance of the Lichdragon. This Remembrance can be traded with Enia at the Roundtable Hold for one of two powerful incantations:

  1. Fortissax's Lightning Spear: A high-Faith incantation that summons two red lightning spears to strike the ground.
  2. Death Lightning: An incantation that replicates the dragon’s ability to call down death-inducing lightning strikes.

Crucially, after the dragon is dead, the player can find the Mending Rune of the Death-Prince on Fia’s body. This is a key quest item used at the very end of the game after defeating the final boss. Choosing to use this rune will repair the Elden Ring with the principle of Life within Death, triggering the "Age of Duskborn" ending and altering the fate of the Lands Between.

Summary of Finding the Lichdragon

The location of Lichdragon Fortissax remains one of the most elaborate secrets in Elden Ring. It serves as the culmination of the game's lore regarding Godwyn the Golden and the Ancient Dragons. To summarize the path: progress Ranni's quest to flip the Carian Study Hall, claim the Cursemark of Death, travel to the depths of the underground via the Valiant Gargoyles' coffin, and follow Fia's path to the Prince of Death's Throne. While the journey is long and the battle is fierce, the reward is a deeper understanding of the game's mythos and access to some of the most visually stunning incantations in the game.