He once served with his Chapter in a campaign against the Tyranids on the planet Hegelian IX. At the time, he was deployed with the Death Company into the planet's catacombs in order to pursue the fleeing xenos, where he and his comrades succumbed to the terrible effects of the Black Rage. This led to the company taking out their blood rage against one another; Ashok killed three of his fellow Space Marines before he managed to control his Rage. For the next three years, he became strapped to the Tablet of Lestrallio in his Chapter's Fortress Monastery, where he faced his nightmares. After he emerged from this event, Ashok was presented with the Shroud of Lemartes as a symbol of his mastery of the Black Rage. He had successfully managed to deal with its affects, although he has to combat the signs.
Following this chain of events, he became attached to the illustrious Deathwatch, the Chamber Militant of the Ordo Xenos, where he served under the command of Captain Quirion Octavius. Librarian Ashok was later deployed with his squad to serve under the command of Inquisitor Kalpysia in order to deal with a splinter Tyranid Hive Fleet on the planet Herodian IV. He is the only Librarian to take on three Tyranid Zoanthropes and live.