Zadkiel is a powerful and honoured Epistolary of the Dark Angels Chapter, seconded to the Deathwatch. He is a prominent leader of the Imperial forces in the Acheros Salient of the Achilus Crusade to retake the Jericho Reach.
Indeed, Zadkiel's knowledge of psychic powers and the Warp are of great value to Kill-teams operating in the Acheros Salient.
However, Zadkiel nurses a deep-seated grudge against the Space Wolves Chapter, and he has little patience for any of the sons of Leman Russ, particularly Watch Fortress Erioch's Master of the Forge, Harl Greyweaver.
Zadkiel's history is oft speculated upon amidst the halls of Watch Fortress Erioch. Known to possess an aloof and proud mien, Zadkiel is rarely forthcoming about his past, but there are a few facts known to his Battle-Brothers in the Deathwatch.
As a young Lexicanium, Zadkiel studied under the Dark Angels Grand Master of Librarians, no less a personage than Ezekiel himself. Zadkiel proved himself under his tutor's strict training, and swiftly ascended the ranks of the Librarium. In time, Zadkiel earned the right to be examined by Ezekiel for induction into the mysterious Inner Circle of the Dark Angels.
The trials that one must overcome in order to be worthy for such an honour are not spoken of outside the Chapter, but there can be no doubt that they are rigorous and exhaustive in nature.
For Zadkiel, the strength of will and determination needed to pass these tests wrought a change within him, and upon his induction into the Inner Circle, his demeanour had entirely changed.
Where once the young Librarian had jested and spoke easily with his Battle-Brothers, Zadkiel had become withdrawn and silent. Where once he sought battle eagerly, Zadkiel turned bloody-minded and recalcitrant.
Ezekiel dispatched his former student to fight alongside the elite 1st Company of the Deathwing for a number of years. Zadkiel once more excelled, honing his own battle skills and developing a talent not unlike that of his teacher -- an ability to read the tides of war and predict the flow of strategy with uncanny precision.
On the nightmare world of Quiette, Zadkiel and the Deathwing fought a savage engagement against a serried tide of bloodthirsty aliens known as the Khrave. Many Battle-Brothers fell, their minds devoured by the xenos foe.
When the aliens massed for a final assault, Zadkiel marshalled his will and held the line, his psychic powers and Force Sword barring the way until the Battle Barge in orbit could fix upon the Deathwing's coordinates. In a matter of moments, Deathwing reinforcements teleported directly into the fray, assisted by pin-point barrage blasts from the orbiting vessel.
Zadkiel's accomplishments that day earned him a special honour, and the Grand Master of the Deathwing himself granted Zadkiel the right to bear Deathwing heraldry upon his armour from that moment forward.
Inquisitor Ezu Ghraile has assembled a considerable file on Zadkiel, and she fervently believes that the Librarian's history is entirely fabricated -- a clever cover story, she asserts, for Zadkiel's placement in the Acheros Salient. Whilst Ghraile has many theories about the truth of the matter, even she is reluctant to endorse any single explanation without further evidence.
Despite these doubts, even Inquisitor Ghraile has no complaints about Zadkiel's service to the Deathwatch. The Librarian regularly assists Kill-teams with strategic and tactical planning for missions in the Acheros Salient, and Zadkiel has led a number of assaults upon key Chaos Space Marine leaders in the Blood Trinity region.
Zadkiel regularly meets with Space Marines seconded to the Deathwatch from Successor Chapters of the Dark Angels, and he has built a rapport with many of these Space Marines who are so far from familiar surroundings.
In the last five Terran years, Zadkiel's attention has sharpened upon a particular world in the Acheros Salient, a foully polluted Fortress World known as Malehi. A battle force of Dark Angels Space Marines were cut down upon that world by a Stigmartus ambush.
There are some reports that claim that Stigmartus Cult-General Elak Sarda has taken a meteorite-forged sword from the fallen Dark Angels captain, possibly one of the famed Heavenfall Blades prized by the Dark Angels Chapter.
- Deathwatch: The Jericho Reach (RPG), pp. 20-21