Hyperion

Zael Effernetti was a low-hiver from Eustis Majoris who at age eleven or twelve, early in the 4th Century of M41, became involved in the banishment of Major Daemon Slyte by Inquisitor Gideon Ravenor. His nascent psyker abilities later lead to his induction, as Brother Hyperion, in the Order of Grey Knights, the Chamber Militant of Ordo Malleus, where he achieved early notoriety as the "BladeBreaker," and was eventually promoted to Prognosticar (Warpseer) in the 666th Chapter's Librarium.

Origins
Effernetti was born c. 390.M41 in the lower levels of Petropolis, a major hive in the industrial world Eustis Majoris of the Angelus Sub-sector. His parents died in a hivepox outbreak when he was a child while his last surviving family member, a grandmother, died when he was eleven years old. Like many lowhivers, he became addicted to the illegal psycho-active drug flect around that time. A street urchin, and physically stunted because of the polluted environment and harsh living conditions, he lived in abject poverty, using his wits to score the next flect hit or "look." It is likely that his addiction triggered innate, unique psyker abilities that eventually brought him to the attention of Inquisitor Gideon Ravenor.

Ravenor and Slyte
Ravenor and his retinue were investigating the flect trade in the Scarus Sector as part of a larger investigation involving the recidivist Cognitae Zygmunt Molotch, and arrived in Eustis Majoris in 404.M41 during the course of the investigation. Ravenor's team came across Zael and was using him as a way into the lowhive flect-dealing syndicates, when Zael's abilities were revealed -- Zael himself was unaware of his unique "gifts." Ravenor described him: "A low-hab stack-runt from Petropolis, a vagabond kid, and also a nascent psyker, undetected by the periodic sweeps and examinations. Not just a psyker, a mirror psyker, that rarest of rare beasts." Subsequently, Ravenor took Zael under his care in order to find out more, and possibly exploit his abilities. Mirror psykers can passively pick-up telepathic communications, even private ones, which they can amplify and "resend." This property is usually just the visible tip of additional, and extremely powerful psyker abilities.

Ravenor and team had been given information that an extremely powerful daemon of the Major Arcana called Sleet or Slyte was going to incarnate in the early years of the 4th century M41 in Eustis Majoris. Furthermore, that this event would be caused by someone close to Ravenor; interpreting a complex series of clues and events, Ravenor suspected that Slyte would manifest through Zael. In a highly unorthodox but typical move, Ravenor did not execute the boy outright as most Inquisitors would have done. In the meantime, Zael collapsed under "psychic assault" during a Cognitae-related mission; with Zael under coma, Ravenor tasked Wystan Frauka, a member of his entourage who was an untouchable, to guard him with instructions to kill him at the slightest suspicion of daemonic manifestation.

However, Zael's coma was self-induced. Zael was not a vessel for Slyte; on the contrary, he had realised that Carl Thonius, Ravenor's Interrogator, was actually Slyte-in-waiting, although he had no tangible proof. He knew that Thonius/Slyte was suspicious of the boy's abilities and would kill him as the only threat to final incarnation, so he faked his "collapse" and coma, hoping to stay alive and take advantage of the situation at a better time. Thanks to his psychic ability and natural intelligence, he achieved an impossible feat: he managed, while under coma, to psychically communicate with Frauka who was an untouchable, eventually imbuing him with psychic touch. Frauka, grateful over this proof that he had (or had acquired) a soul, kept their communication private, and vowed to protect Zael and help him in thwarting Slyte.

Eventually Frauka, "worn" by Zael, manage to convince Ravenor that Slyte would use Thonius as a gateway, which lead to Ravenor's subsequent banishment of the daemon in 404.M41. In the meantime Ravenor had declared Official Rogue status, which the Inquisition authorities charged he overstepped, and after the Slyte affair he was subject of an Inquisition trial in Gudrun. As Ravenor's retinue disbanded, Zael was put in the care of Ordo Hereticus Inquisitor Lilith Abfequarn.

On Titan
After initial processing, Inquisitor Abfequarn took Zael from Gudrun via Black Ship to Titan, and the Ordo Malleus Headquarters Base. In her report, Abfequarn stated that his psyker potential could be "unlocked" in a controlled manner. The Grey Knights Prognosticars also had a favourable opinion of Zael's disposition (it later transpired they thought he could become a Prognosticar himself). So in 406.M41, after his mind-wiping and passing the initial 99-day assessment, Zael was accepted as a candidate Grey Knight, and started the decades-long training to join the Order.

Following the start of the formal training he was given the name Hyperion. He eventually received the Emperor's Gift (ie gene-seed and implants grown from the Emperor's own DNA) and around 443.M41 became a full knight. By that time his telepathic and other psyker abilities had been honed to a high degree. However he was deemed as lacking the necessary self-control to become a Prognosticar, and he was instead assigned -- primarily as a Pyrokine (a witchfire warlock) -- to Squad Castian of the Eighth Brotherhood, under Justicar Galeo.

Bladebreaker
In 444.M41 Squad Castian assisted Inquisitor Annika Jarlsdottyr of Ordo Malleus in investigating a Space Wolves vessel that was drifting powerless in the void. The investigation turned up proof that Chaos was engaged in a hitherto unknown, major campaign against the important hive world Armageddon. The magnitude of the campaign, eventually known as the First War for Armageddon, became obvious when it was revealed that a Major Daemon of Khorne, previously the Primarch Angron of the Traitor World Eaters Legion, was leading the invasion. The Grey Knights responded to a request for help from Jarl Logan Grimnar, the Chapter Master of the Space Wolves, who were at the forefront of the planet's defense.

Squad Castian joined an ad hoc "Ragged Brotherhood" of Grey Knights under Talemar Aurellian, First Captain of the Eighth Brotherhood, and along with a hastily mustered Inquisition force, made course to Armageddon at top speed. Upon arrival, Grimnar bade them to wait in orbit until the right moment to confront Angron would present itself. Grimnar also secured Aurellian's word that innocent civilian population and defending Imperial Guard units would not be purged by the Inquisition after the war's end solely for the "crime" of witnessing Chaos and its hunters, the Grey Knights.

When the call came, the Grey Knights teleported in the midst of the advancing Chaos horde, surrounding the gigantic Major Daemon. Taking heavy losses from its enormous, tainted weapon (the "Black Blade"), the Knights approached inflicting their own punishment, and eventually Squad Castian, including Hyperion, were at melee distance. After Angron mangled the squad, Hyperion was the only one standing. Trying to protect a still surviving squad mate, in a tremendous display of faith, power, and effort, Hyperion used his psyker ability to shatter the Daemon's blade -- while he himself collapsed. Captain Aurellian then confronted the bladeless ex-Primarch and managed to banish it to the Warp, though at the cost of his own life.

Hyperion was one of only 13 Knights to survive the battle, out of a brotherhood of 109. Found alive though in terrible shape by Space Wolves in the hellish field after the battle, he soon acquired the honorific "Bladebreaker" for his feat. He had to eventually be put in stasis in order to survive, and undertook surgery that replaced half his face and head with augmetics, eventually reporting back to duty more than 4 months later.