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, and the boss of The Sunless Cell Strike, as well as the The Lightblade Strike after his resurrection as Alak-Hul, the Lightblade, thanks to a Hive Ghost under the Lucent Brood.

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.

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 Thrall at 25% health intervals, with Cursed Thrall being 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.

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