Ordo Xenos

The Ordo Xenos (Alien Hunters), together with the Ordo Malleus (Daemonhunters) and the Ordo Hereticus (Witch Hunters), is one of the primary sub-divisions of the powerful and secretive organisation known as the Imperial Inquisition. The Ordo Xenos is served by its Chamber Militant, the Deathwatch Space Marines, who draw on Veteran Astartes from Chapters all across the Imperium of Man to form the Deathwatch's Kill-teams and destroy the many foul xenos threats to the survival of Mankind.

History
The Ordo Xenos was created after the Emperor of Mankind was interred in the Golden Throne at the end of the Horus Heresy, though in fact the Inquisition had been founded earlier at the express order of the Emperor after the Horus Heresy had begun from a group of skilled Imperial agents and Loyalist Space Marines from the Traitor Legions who were tasked with uncovering and destroying every threat to the Imperium of Man, from both without and within. After the Horus Heresy, the Ordo Xenos gradually evolved from that group of Inquisitors who were primarily interested in investigating and studying the alien races of the Milky Way Galaxy and eliminating any threat to the Imperium that these xenos represented.

Armed with the best human and alien technology available, extremely knowledgeable about their foe, and filled with the xenophobic hatred for non-human species that drives so much of Imperial culture since the Horus Heresy, the Ordo Xenos can respond to any alien threat. Their tactics vary depending on the situation and the level of alien taint revealed. Where the threat is subtle, they will use guile and stealth, wielding their power as if it was a scalpel used to cut out a growing malignant cancer. When the alien menace is great, the Inquisitor can commandeer the aid of entire regiments of the Imperial Guard and the special contingent of Space Marines drawn from every existing Chapter who are specifically attached to the Ordo Xenos as its Chamber Militant and are known as the Deathwatch.

Deathwatch
When the alien threat is too great for even the requisitioned Imperial Guard or Planetary Defence Force troops of the Inquisition to handle, the Inquisitor will call on the elite Battle-Brothers of the Deathwatch, who operate in Kill-teams made up of elite Space Marines from all of the Space Marine Chapters in the Imperium. All Deathwatch members wear black Power Armour except for one shoulder plate which bears the colors of their original Chapter (so as not to dishonor their power armor's Machine Spirit) and the other is emblazoned with the unique Chapter badge of the Deathwatch. Certain Chapters make for great Xeno-hunters, like the Ultramarines (with their long and infamous experience with the Tyranids during the Battle of Macragge) or the Crimson Fists (with their experience against the Orks during the Battle for Rynn's World).

The Ordo Xenos is well-known for either being extremely ponderous in its operations or extremely quick to act. A major example of their slowness to act was when the Tau first made contact with Imperial Planetary Governors on the Eastern Fringe of the galaxy and these aliens' technology was allowed to penetrate all the way to Terra through the Imperial trade routes as their technology was bought and sold by Imperial merchants. However, at times the Ordo Xenos can truly bring the Emperor's justice to those alien races who seek to challenge human domination of the galaxy, a prime example of which was seen during the Damocles Gulf Crusade in which an Ordo Xenos-led Imperial Navy battle group spearheaded an Imperial Crusade deep into Tau space, although its progression slowed to a halt when they reached Dal'yth, one of the core Sept worlds of the Tau Empire. It is worth noting that, with the arrival of Hive Fleet Behemoth in the galaxy from the intergalactic void, the forces of the Damocles Crusade was forced to withdraw from their siege of Dal'yth to attend to that first massive Tyranid invasion.

The Deathwatch Kill-teams may specialize in defending or attacking any known alien race, including the Tau, Tyranids, Necrons, Orks or even Eldar; it depends upon the experience of the team. A Kill-team can be composed of groups of 5, 10, or even 20 Astartes in rare cases depending on the size and scope of the alien problem. In extreme circumstances, they will operate alongside other armies of the Imperium, including Imperial Guard Regiments under Inquisitorial control or even elements of other Space Marine Chapters that have responded to the Inquisition's request for assistance. When a Battle-Brother leaves the Deathwatch after his term of service to return to his original Chapter, he gains the honour of keeping the Deathwatch's silver badge on his Power Armour's left shoulder plate.

Notable Ordo Xenos Members

 * Inquisitor Agmar - As a young member of the Ordo Hereticus, Agmar led attacks upon Ichar IV's capital city of Lomas to break up rebellion among strange alien cult members. It turned out that the rebellion was created by a massive Genestealer infestation. With the Adeptus Arbites, he destroyed enough of the Genestealers' defenses to allow the Ultramarines to seize back the planet. It was then that Agmar's Astropaths felt the approach of Hive Fleet Kraken and it was his initiative that led to the breaking of Hive Fleet Kraken at Ichar IV.
 * Battle-Brother Artemis - Artemis was originally an Astartes of the Mortifactors Chapter of Space Marines. Artemis commanded Deathwatch Kill-teams against the xenos known as the K'nib in the Donorian Sector. This was done at the request of the Kaslon Imperial Guard Regiment. Artemis slew Alcayde and ended their attack upon Imperial space, even though the credit was given to the Kaslon regiment. He is quoted as saying: "Do not ask, 'Why kill the alien?' rather, ask, 'Why not?'"
 * Inquisitor Gregor Eisenhorn - An Amalathian member of the Ordo Xenos, Eisenhorn was the infamous Inquisitor who orchestrated the downfall of Quixos the Bright and Pontius Glaw using a stolen daemonhost named Cherubael, a former tool of Quixos. He seemingly vanished soon after the downfall of Pontius, having been declared a heretic by Inquisitor Osma of the Ordo Malleus and this bad reputation stayed with him despite attempts to clear his name by other Ordo Xenos members.
 * Inquistor Lord Kryptmann - Well-versed through hard experience in knowledge of the Tyranids and their infestation techniques, Inquisitor Kryptmann was responsible for first identifying the Genestealer infestation preceding Hive Fleet Leviathan. He later authorized the largest single act of genocide the Imperium has ever inflicted on itself by abandoning or destroying all worlds in Hive Fleet Leviathan's path. For his actions he was issued a Carta Extremis and was stripped of his title and position in the Inquisition. However, this did not stop him and he soon led his loyal Deathwatch Astartes to capture live Genestealers, place them in stasis, and use them to lure the Hive Fleet into the worlds controlled by the Orks of Octavius, slowing down the Hive Fleet's progress towards Terra while it sought to digest that massive Ork empire.


 * Inquistor Reynaard - Reynaard discovered a cult worshiping aliens on Mandall IV. Using a Deathwatch kill team, he attempted to destroy the cult, which proved to have taken over most of the capital city. After escaping, Reynaard returned with over 500,000 Imperial Guard troops and eradicated all in the city.


 * Amberley Vail - Acolyte of the Ordo Xenos. Featured in the Ciaphas Cain series, she acts as the editor of the Cain Archive. It has been suggested that her relationship with Cain is more than professional.


 * Inquisitor Gideon Ravenor - Once a handsome and lean man, Ravenor was crippled on Thracian Primaris and is now litle more than crippled flesh living inside a heavily armoured casing tha acts as a grav chair. In his crippled form, however, his psychic abilities have strengthened, and with the help of Psi boosters attached to his grav chair, he has become a much more powerful psyker, in the high Delta, low Gamma range. He once served with Inquisitor Eisenhorn, however sinceEisenhorn's disappearance, Ravenor has taken charge of Eisenhorn's old retinue of Acolytes and Throne Agents to seek out and destroy all alien threats to the Imperium.