Later during the [[Horus Heresy]] Revuel Arvida was transformed in an arcane ritual into '''Janus'''{{Fn|5}}, who would go on to become the first [[Grey Knights Supreme Grand Master|Supreme Grand Master]] of the [[Grey Knights]].

Stationed amidst the Thousand Sons fleet, Arvida missed the [[Battle of Prospero]] and in fact remained ignorant of it for some time. Several weeks after dispersing, his Captain, [[Menes Kalliston]], became worried at their inability to contact [[Prospero]], and decided to turn his vessel - the ''Geometric'' — towards home. Severe [[warp storms]] hindered their progress, as well as attacks from Imperial forces they attempted to communicate with; it was six months before the under-crewed ''Geometric'' achieved orbit over a desolate and burned planet. Arvida did not especially agree with Kalliston's decision to return home, feeling that there were other mysteries surrounding what had happened to their legion to solve first, but loyally agreed to accompany his Captain to the surface.{{Fn|1}}

Returning to their landing site, Arvida discovered it overrun by several squads of [[Angron]]'s Legionaries. Realising that he had to run and hide, his revulsion at the World Eaters' actions made him look once more into the future and find the thread of fate that would result in the death of the World Eaters' Captain present, blowing his head off with prescient timing, before making his escape. Operating on the assumption that the ''Geometric'' had probably been destroyed, Arvida resolved to hide himself away and begin a personal quest to discover exactly what had happened to bring ruin upon Prospero, and then to use all the knowledge at his disposal to see the forces behind it destroyed. His own precognitive powers were able to inform him that he would not die upon Prospero.{{Fn|1}}

After an unknown amount of time passed Arvida discovered the Keshig of [[Jaghatai Khan]] fighting against the shades of the Psychnuiein that had been created by the psychic devastation wreaked on Prospero. Using his psychic powers to save them he made contact with Qin Xa, leader of the Keshig, and offered to help them locate their missing Primarch. Arvida later fought with the Keshig against the [[Deathshroud]] while [[Mortarion]] and Jaghatai Khan fought, and ensured that the [[White Scars]] could escape Prospero by creating a beacon for teleportation with his powers. He was accepted as a guest of the White Scars and was last seen with them aboard the flagship ''Swordstorm''.{{Fn|2}}

Ultimately, [[Targutai Yesugei]] sacrificed himself by activating the space station ''[[Dark Glass]]'', which punches a hole through the warp and into the [[Webway]]. Arvida was tasked by Yesugei's final message to lead the Scars back to Earth, and he uses his great psychic might to guide the fleet while the ships are assaulted by demons. After finally guiding the fleet closer to Earth, he begins to succumb to the change and is rendered unconscious. [[Khalid Hassan]], agent of Malcador, arrives and promises the Scars that Malcador will treat his condition and that they have been waiting for Arvida to come.{{fn|4}}

{{Spoiler|source=The Last Son of Prospero (Short Story)}}

Deep in the [[Imperial Palace|Imperial Dungeon]], [[Malcador (Character)|Malcador]] attempted to bind a fragment of [[Magnus the Red]] which had remained on Terra after his ill-fated message damaged the [[Webway Project]], intending to use the resulting 'abomination' to guard the gate, as the [[Emperor]] had originally intended Magnus to do. The Khan demanded the Sigillite stop, but arrived too late. When Arvida's mutated body began to be consumed by psychic fire, unable to contain the power of the shard, Malcador went to kill him, but the Khan insisted that the sorcerer was his ward and must be given his chance. Smashing the arcane machinery in the chamber, he freed the amalgam of Magnus and Arvida from the suppression fields and wards.{{fn|5}}

At the conclusion of the [[War of the Beast]] in 546.[[M32]], the mad [[Grand Master of Assassins]] [[Drakan Vangorich]] purged the [[High Lords of Terra]] in what became known as [[The Beheading]]. The last surviving High Lord, [[Inquisitorial Representative]] [[Wienand]], was made aware of the existence of the Grey Knights and urged to seek out Janus shortly before the death of co-Representative [[Veritus]]. Wienand was given Veritus' key and was able to travel to the [[Citadel of Titan]], where she met Janus. Despite her encounters with many Space Marines, she was overcome by his presence.{{Fn|7}}

Arvida was stocky, with a bull neck and angular jaw, looking like a typically pugnacious Space Marine. A member of the Corvidae, he was skilled at precognition, though found his powers harder to access in the time after the fleet dispersal. Arvida was noted to be a skeptical soul by his Captain, and required convincing about the wisdom of investigating the ruins of Prospero. Kalliston appealed to Arvida's interest in learning hidden secrets and recovering objects of knowledge in order to tempt him into agreeing with the return home.{{Fn|1}}

Unusually for a member of the Thousand Sons, Arvida professed to never have had complete faith in the doings of his [[primarch]], [[Magnus]]. The ruins of razed Prospero only served to convince him that he had been right to be doubtful of some of Magnus' strategies, and resolve that it was folly to continue to follow them now, instead dedicating himself to a his new quest.{{Fn|1}}

{{Trivia}}

*Arvida is a Nordic name of compound construction. Currently used as a feminine forename, [http://www.nordicnames.de/wiki/Arnvi%C3%B0r the words it derives from,] when literally translated, mean 'eagle-man'.

*[[Known Members of the Thousand Sons]]

*{{Endn|1}}: [[Rebirth (Short Story)]]

*{{Endn|3}}: [[Allegiance (Short Story)]]

*{{Endn|5}}: [[The Last Son of Prospero (Short Story)]]

*{{Endn|6}}: [[Codex: Grey Knights (5th Edition)]], pg. 6

{{DEFAULTSORT:Arvida, Revuel}}

[[Category:Characters (Thousand Sons)]]