Vaniel was the Chief Librarian of the Ultramarines Chapter, when the Ork forces of The Beast invaded the Imperium. Once Ullanor, was determined to be where The Beast's forces originated from, Vaniel joined as part of the strike force sent to invade the world, in order to kill the Warboss. However, when the strike force arrived at Ullanor they were unable to use their ships to discover the Warboss' location, due to the world being enveloped in psychic energy. With time running short, Chapter Master Koorland, asked for the Space Marine Chapters present to gather their Librarians together; in order for them to combine their powers, so they could pierce Ullanor's physic veil. Vaniel was charged with focusing the Librarians' power for the ritual and they entered into a connected trance, where they were able to discover that The Beast was present in an Ork city known as Gorkogrod. However disaster struck before they were able to learn the exact location of the city, when the Chief Librarian was overwhelmed by the Orks' physic energy. As Vaniel served as a conduit for the ritual, the Ork's energy soon spread to the rest of the Librarians present and nearly overwhelmed all of them. Only the Rune Priest Thorild was able to initially resist the Ork's physic power and he was able to help most of the others resist before he broke the trance they were in. As soon as he did so though, Vaniel and two other Librarians, who had fallen under the Ork's power, began attacking those around them. The maddened Chief Librarian was able to kill the Librarians Redolphio and Carrigan Nos before he was killed by the Rune Priest Thorild; which severed the ritual's connection to the Ork's physic energy and ended its influence on the Librarians.