Nameless King

The Nameless King is a supporting antagonist and optional boss in Dark Souls III. Presumed to be the long forgotten first-born son of Gwyn, he betrayed his father and chose to side with the Everlasting Dragons.

Biography
The Nameless King was once a powerful warrior who served under Gwyn. Taming his own Stormdrake named the King of the Storm, the warrior was seen as a living god of war given his respect for arms and nothing else. The heir of lightning miracles, many dragon slayers sought to be trained under the warrior for his strength and wisdom, including Ornstein, one of the Four Knights of Gwyn.

That was until during the war with the dragons, the warrior suddenly chose to sacrifice everything to ally with the dragons against the lords and the Age of Fire. Despite his immense power, he was ultimately defeated, stripped of his status, and banished from Lordran. To ensure that nobody would follow in his traitorous footsteps, Gwyn ordered the shrines and statues of the warrior to be demolished so the name of the "Nameless King" would be forgotten from the annals of history. Although those close to worshiping the remnants of the king's broken idols still had vacant memories of the king and his actions, such as Ornstein and Knight Solaire.

The Nameless King can be summoned to the Archdragon Peak by ringing the Great Belfry. When the area becomes shrouded in storm clouds, the Nameless King emerges from the sky riding the King of the Storm into battle. The Stormdrake attacks by shooting fire from its mouth. The Nameless King shoots lightning from his spear and if approached, he swipes and slams his spear towards the player. Attacking the head or the King himself deals more damage to the King of the Storm. Enough hits can cause the Stormdrake to stagger, allowing the player to perform a riposte and deal critical damage.

Once the King of the Storm goes down, the Nameless King kills his Stormdrake to boost his lightning powers. Even without a dragon mount, the Nameless King is very agile and his combos can quickly catch the player off guard should they dodge too early. His attacks can be followed by area effects of wind or lightning. Similarly to Ornstein, he can lunge his spear into the player and electrocute them for massive damage. But like the King of the Storm, he can be riposte for critical damage when poise-broken.

Once the Nameless King is defeated, he drops his boss soul and the Great Belfry is rung once more, which sends the storm clouds away and returns Archdragon Peak back to normal.

Trivia

 * The first phase with the King of the Storm can be skipped in New Game Plus cycles by using the Sunlight Spear miracle and aiming it at the Nameless King.
 * Some notes of the Nameless King's theme sounds like Gwyn's theme, implying the theory that he is Gwyn's son.