Alak-Hul, the Darkblade

"Oryx gave me no task. Therefore I must task myself, with Oryx's ending."

- Alak-Hul

Alak-Hul, the Darkblade is a Hive Darkblade Knight, foster son of Oryx, the Taken King, and the boss of The Sunless Cell Strike. After being killed by the Guardians, he was resurrected years later as Alak-Hul, the Lightblade by a Hive Ghost of the Lucent Brood, and became the boss of The Lightblade Strike.

Biography
"Eris, why did the Darkblade rise against Oryx?" "The Wizard Verok was his mate. He slew a legion of Thralls in her name. Marched on the King's throne at the head of an army built on hate and pain." "How... romantic."

- The Ghost and Eris Morn

Alak-Hul and his consort, Verok, were present at the Hellmouth when Eris Morn and Eriana-3 led their fireteam to assassinate Crota, Son of Oryx. It was Alak-Hul and Verok's spawn that killed the Titan Vell Tarlowe, with the former delivering the killing blow upon his axe.

Following the failed raid, Alak-Hul and Verok instigated a rebellion against Oryx, but the rebellion was put down. Alak-Hul's motivation was twofold: first, because he felt neglected by Oryx (which was deliberate, as Oryx wanted Alak-Hul to become a "hungering blade"), and second, to appraise himself in the eyes of Verok. Alak-Hul was captured by Oryx's warriors, and the Taken King decreed that Alak-Hul be imprisoned aboard the Dreadnaught, never to see the light again. But after Oryx retreated from the material realm, Eris wanted to make sure Alak-Hul couldn't take over as the "King of the Hive" and to avenge Tarlowe, ordered for his elimination, and so a fireteam went down into his dark cell and killed him.

Rebirth as the Lightblade
At some unknown point, several years after the Darkblade's death, a Hive Ghost would come across and resurrect Alak-Hul, re-titled as the Lightblade. Alak-Hul would then join forces with the Lucent Brood and become a formidable ally. He was tasked by Savathûn, the Witch Queen to guard a temple commemorating Oryx, which housed a piece of the Tablets of Ruin.

Assisted by Lightbearing Warriors and normal Knights Disciples as his personal guards, the Temple was well defended. This was until a Fireteam of Guardians, following a lead by Fynch about a potential clue from the temple, would run into Alak-Hul who was away from his post, who then fled back to the temple. Facing off against his Warriors and Disciples, along with hitching a ride on a ferry, and evading Scorn to reach to the temple, the Fireteam would enter the monument while being caught by surprise of the Lightblade’s arrival. Gifted with Arc light powers and guards at his disposal, the Lightblade tried to defend the temple from the Guardians but was slain as a result. However, Alak-Hul’s Ghost would escape from the temple, leaving his body behind.

The Sunless Cell
"The Darkblade is formidable. And left unchecked, a worthy successor to lead the Hive."

- Eris Morn

The fight with Alak-Hul will be deep in his cell, so it will be almost pitch black, limiting one's field of vision. He is armed with an axe. He will appear to vanish from existence only to teleport to another position of the arena after taking a certain amount of damage from ranged weapons; if attacked with a Super or a Sword he will not vanish or teleport. He will summon waves of Thralls at 25% health intervals, with Cursed Thralls mixed in at the lower amounts. When on low health, Alak-Hul will become enraged and charge his foes down to cut them to bits.

The Lightblade
"Careful. The knight guarding this place? He's an old rival of Oryx and he's no joke."

- Fynch

Alak-Hul will appear multiple times throught the Lightblade strike before fighting him as the boss. He will first appear near the beginning, at the door of the Queen's Bailey, and then again battling Scorn in front of the Temple of the Navigator. Both these times, he will stay back and blast the Guardians and Scorn with Vicious Light, retreating after taking little damage, or after his minions are killed.

The actual fight against Alak-Hul takes place in a large and spacious room, dedicated to Oryx, his former rival. Soon after the player enters the arena, Orbs of Power will rain down around the arena. Alak-Hul will then slam the ground with his axe as he spawns in the middle, hitting anyone close enough. Alak-Hul will be highly mobile during the fight, chasing the player between the lower and upper floors, as well as the central dais. At range, the Lightblade will blast Arc projectiles towards the player in large and damaging bursts. These have a slight homing capability and can be extremely deadly if the player is caught on a lower level, or in midair. His deadliest attack is his axe though, being really fast, hitting a large area, and capable of killing a Guardian in a single strike, even at full health. At 80% health, a wave of Thralls will spawn to support Alak-Hul. At 65% and 33% health, the boss will teleport to the central dais and will cease attacking, become invulnerable, and summon ten Cursed Thrall, two Disciples and a Warrior, as well as rain down more Orbs. When the Disciples and Warrior are slain, Alak-Hul will resume the chase. After each invulnerability phase, as well 50% health, Revenant Knights, Acolytes and Thralls will spawn to attack. When he reaches 50% health, Alak-Hul will lose his helm, causing him to become enraged and chase the players at higher speed and with faster attacks.

In Master and above difficulties of The Lightblade strike, Barrier Knight Champions will spawn in place of the Revenant Knights.

Trivia

 * Alak-Hul's name can be considered a portmanteau of two Sindarin words from J.R.R. Tolkien's fictitious Elvish languages, specifically the root "alak-" (rushing) and "hûl" (cry of encouragement in battle). This is illustrated by the fact when he is on low health and the screen text says "Alak-Hul charges his foes".
 * After dealing enough damage, bringing him to low health, Alak-Hul's helmet will break, revealing a disfigured oval-shaped head.
 * In Destiny 2, a new class of Hive enemy called Darkblade was introduced, which feature characters that resemble Alak-Hul in both appearance and abilities.
 * It's possible that Alak-Hul was the first of the Darkblade subtype since they all bear similarities to him.
 * Unlike most Hive Knight bosses, Alak-Hul is shown to have the same sounds as a Taken boss would have.
 * Aside from Oryx, Alak-Hul is the only Hive in Destiny 1 that can teleport without a portal.

List of appearances

 * Destiny: The Taken King
 * Destiny 2: The Witch Queen