Venerable Xandor is a Deathwatch Dreadnought stationed on Fort Excalibris and was among the Kill-Teams taken by Excalibris' Watch Commander Feron, to purge the Genestealer Cult that had infested the Imperium Mining World Cagalian IX. However, when the Kill-Teams attacked the Cult, known as the Cult of the Rusted Claw, they were beaten back and were shocked to discover that the Cult was larger and more powerful then they had suspected. Their failed attack caused Feron's Kill-Teams to suffer many casualties and he decided, that instead of fighting to the death against the Cult of the Rusted Claw's unfathomable numbers, they would retreat and inform the Imperium of what had happened on Cagalian IX. As the Deathwatch retreated to their evacuation point however, they were attacked by a large force of the Cult and in the ensuing massacre, Feron and many of his Kill-Teams were killed. Thanks to the efforts Xandor though, who destroyed a larger number of Genestealers blocking the extraction point, the Codicier Velim and his ravaged Kill-Team were able to escape off world and bring word of the Cult's threat to the Imperium. It is not known however, if Xandor was able to escape with them.