Cypher

Cypher is a character in Warhammer 40,000. He is an enigmatic character, a legend on almost every world of the Imperium.

Background
The terrible secret of the Dark Angels is that during the Horus Heresy some of their brethren fell to Chaos, corrupted by the Legion's second in command, Luther. The renegades were defeated in a battle that destroyed the Dark Angels' homeworld, Caliban, but many of the traitors survived to be cast through space and time by the Chaos gods. The events of Luther's betrayal are known only to select few amongst the Dark Angels and their successor Chapters. The defeated survivors are known as The Fallen, mercilessly hunted down and made to repent by the Interrogator-Chaplains of the Dark Angels.

Cypher, one of the Fallen, continually draws the attention of the Dark Angels. He is believed responsible for many acts of instability across the Imperium, and is hunted by the Dark Angels with zeal even greater than that reserved for 'normal' Fallen. Even when he is captured, he soon vanishes, whisked away by his mysterious patron. Although his immediate presence heralds disorder and strife for the Imperium, it always emerges transcendent from it, stronger than before, which may suggest an intention behind Cypher's actions to make the Imperium stronger through struggle (following the old philosophy of 'what doesn't kill you makes you stronger')

Like many of the Fallen, Cypher wears black power armor matching the pre-Horus Heresy livery of the Dark Angels, covered with white robes. He wields a bolt pistol and a plasma pistol of master craftsmanship, and is so skilled with them he can fire both simultaneously.

Although the Dark Angels believe that they can only gain forgiveness for their actions by "redeeming" all of the Fallen, others privy to the full tale believe that Cypher may have another answer. These people believe that Cypher's seemingly random appearances conceal a path that is slowly leading towards Holy Terra. They also point to the fact that Cypher carries a sword, yet he never draws it. This could be the sword of Primarch El'Jonson, broken in half and then lost during his final battle with the traitor Luther. One theory states that if Cypher manages to enter the presence of the Emperor of Mankind, the sword will repair itself and the Fallen Angels will be forgiven for their transgressions. Another theory states that it is the black blade of Luther and Cypher wishes to use the sword to slay the dying Emperor's mortal body, thus completing the Star Child cycle or defeating the Imperium.

The Voice of the Emperor
It is widely believed by fans that Cypher used the alias of "The Voice of the Emperor" during the worldwide Eye of Terror campaign. Though this was unconfirmed, the description of the Voice of the Emperor, "a hooded figure carrying a sword and a pair of exquisite pistols" - fits the appearance of Cypher to a tee, and Andy Chambers mentions the connection in an article describing the results of the campaign. Although he appeared to be supporting the Black Crusade on the surface, his influence had a polarizing effect, resurging Imperial faith as much as rallying anti-Imperial cult fanatics, along with drawing the Dark Angels into several conflicts where their assistance was of great benefit to the Imperial war effort.

"The Voice" is also mentioned in Warhammer 40,000 Codex: Black Templars, where he is described as a figure wearing ancient, black power armour, devoid of livery. A Black Templars strike cruiser, the Ophidium Gulf, assists a Dark Angels force in pursuit of "The Voice". Although the Black Templars capture him, they were forced to hand him over as the Dark Angels fleet threatened to fire on the Gulf. The crew of the Gulf released the prisoner into the custody of the Dark Angels, and after a single communication back to the High Marshal, disappeared without a trace. Due to the suspicious nature of its disappearance, this has led some fans to believe that the Dark Angels destroyed the Gulf in order to hide their secret shame.

Upon their return to the Rock, the cell in which "The Voice" had been confined was discovered to be empty.

Descent of Angels
In the novel Descent of Angels, part of the Black Library's Horus Heresy series, it is revealed that Lord Cypher is a title used by the Order, the knightly order commanded by Lion'El Jonson during his initial years on Caliban. The bearer of the title is responsible for maintaining the Order's traditions, rituals and ceremonies, and is an influential advisor to the Order's leadership. Upon taking the title, the Lord Cypher gives up his birth name; it is also forbidden for anyone else to use or even know it.

Although the character Cypher does not appear in the novel, it seems implied that he is the last bearer of the title, and that therefore Cypher is not his birth name. Some fans believe one of the characters in Descent of Angels will become Cypher in a future novel.