Prince Flamadin is an aspect of the Eternal Champion and the fourth and final identity assumed by John Daker, and friend and ally to Ulrich Von Bek. Prince Flamadin is a bearer of the Black Sword, which he wields in the form of the Dragon Sword. He also possessed the Actorios Stone long before it was set into the Ring of Kings which Elric of Melniboné would eventually inherit.
The original Prince Flamadin was the twin brother of Princess Sharadim, set to become Empress of their home realm of Draachenheem, one of the Six Realms of the Wheel. While Flamadin would often go on adventures, his sister was secretly gaining the support she needed to become Draachenheem's War-Empress. It is custom there for royal siblings to marry, but when she recalled Flamadin home to ask he honor that custom in order to consolidate her political power, he refused and planned to tell the realm of her schemes. So she fatally poisoned him and claimed she exiled him for attempting to kill her, making him out to be a disgraced ex-Prince. She kept his body preserved in a secret room to perform strange rituals upon it.
When John Daker completed his existence as Urlik Skarsol, Sepiriz convinced him to re-board the Dark Ship That Sails Between the Worlds. Its crew, the Blind Captain and his brother the Steersman, took him to Maaschanheem, the Six Realms of the Wheel. A new body identical to Flamadin's was waiting for him there, standing next to Ulrich Von Bek. When he exited the boat, he was in the Prince's body, and Ulrich became his closest companion on their quest for the Dragon Sword. Ulrich explained to Daker that he was a German Count of Saxony who attempted to assassinate Adolf Hitler during WWII but was captured by the Nazis. He escaped only to find himself in the Middle Marshes and then with Daker in Maaschanheem, a realm dominated by Hulls and Anchorages, mobile city-ships.
They became guests of Baron Captain Armiad-naam-Sliforg-ig-Vortan and his binkeeper Mopher Gorb after some of their crewmen died in a battle they instigated against the two. Their ship, the Frowning Shield, took the pair to the Massing, a trading port that briefly opens up between the Six Realms, because Armiad believed his fellow captains would be impressed that he keeping company with a prince. During this time, they befriend Bellanda, a woman who lives on the ship, with whom Ulrich left his Walther PPK .38. After the other captains told Armiad that Flamadin was a disgraced ex-prince, he was angered at Daker and Ulrich for "tricking" him into "deceiving himself", and tried to have them killed at the Massing after they interrupted a slave trade he was making with the "cannibal" Ghost Women. Alisaard, an Eldren warrior who looks and sounds exactly like Ermizhad, and her fellow Ghost Women were forced to intervene to save them, breaking several inter-realm laws in the process.
The women took the pair to their current home realm, Gheestenheem, where the Eldren reveal that they do not eat their man-slaves after mating with them, but treat them well thereafter. They also reveal why John was brought to the Six Realms in the first place: to free the female cosmic dragon in the Dragon Sword. Its counterpart, a male cosmic dragon, had guided the male Eldren of a world where they were being hunted by the Mabden to a safer place without Mabden. After he succeeded, the female dragon then left with the female Eldren to guide them there. But before she could complete her task, she was trapped by the Dragon Sword at the moment of its creation, as Black Swords have a habit of drawing in and trapping demons and other such creatures within them at the time they are forged.
With the dragon taken midway, the Eldren were left trapped in the Six Realms, and their race would soon perish unless the Dragon was freed to guide them home. The Eldren saved John because they were told Flamadin was the only one who could safely wield the sword. After the Eldren women gave Daker the Actorios Stone and explained their predicament to him, he felt he owed it to his Eldren Princess Ermizhad to save them. He and Ulrich went on a quest across the Realms of the Wheel to find and recover the Dragon Sword, in which they were joined and guided by Alisaard. During the course of their adventure, she and Ulrich fall in love, and Daker couldn't help but feel jealous of him for it.
Sharadim sought the Dragon Sword so she could trade it to Archduke Balarizaaf, a Chaos Lord trapped at the center of the Six Realms, in return for the power to conquer them all and become immortal. Flamadin and his companions sought the sword to stop her, and to free the female cosmic dragon within.
When they find the Dragon Sword, Sharadim steals it using the real Flamadin, whom she turned into a soulless zombie under her control. He briefly sucked out Daker's soul to take the sword, and used it to damage the barrier between the Six Realms and the demon realm enough that Balarizaaf and his army would soon break through. Daker only recovered his soul by reaffirming his belief that he was not Flamadin or the Champion or anyone else besides John Daker. He did battle with Flamadin at the Frowning Shield but was overpowered by its crew. After retrieving his Walther PPK .38 from Bellanda, Ulrich killed Flamadin and Mopher Gorb with its last two rounds and Alisaard killed Baron Captain Armiad with her sword, saving John, and the three killed Armiad's remaining warriors with swords.
Sharadim took the Dragon Sword from her brother's corpse and used it to destroy the Actorios Stone. In doing so, she trapped a different piece of her soul in each of the thousand shards of the Actorios as it sent them each to Limbo. This killed her and allowed Daker to execute a ritual Sepiriz said could only be performed once per cycle of the multiverse: summoning the Warriors at the Edge of Time, an army of Eternal Champions waiting at the Edge of Time for their final battle, to aid him. With the help of the Warriors and the portion of Sharadim's army that would listen to him, Daker defeated Balarizaaf and his army of Chaos and prevented them from invading the Six Realms.
After reuniting with the Eldren women, Daker split the Dragon Sword on the Iron Round, an ancient Eldren anvil, freeing the female cosmic dragon that was trapped within it. She then guided Ulrich and the Eldren women to the new home of the Eldren. Jermays the Crooked told Daker that their descendants would inhabit a land that would become known as Melniboné and that the two halves of the Dragon Sword would be reforged into Stormbringer and its twin, Mournblade.
As Sepiriz promised, Daker then boarded the Dark Ship for the last time. He dreamed about the statues described in The Quest for Tanelorn before waking and disembarking from the ship, only to return to his original life as John Daker in modern-day London. He had now gained a greater appreciation for his normal life than when he left and was confident he would find Ermizhad there in some form or another.