Once the Arcus strike tank was one of the most advanced support platforms available to the Space Marine Legions, but for reasons long since lost to the past, the Adeptus Mechanicus holds the pattern as a slight against the Omnissiah and refuses to produce or repair such vehicles. Without the specialised knowledge of the Machine God’s adepts, the advanced launchers of the Arcus have slowly failed and been replaced with more common rotary launchers and stocks of its rare warheads have dwindled. Now it is used by the Space Marine Chapters that retain examples of this rare pattern as a fast strike tank, racing it forwards to saturate a target area with incendiary devices of a more commonplace provenance and using its renowned speed to escape unscathed, enabling them to clear otherwise redoubtable bunkers and fortresses with brutal efficiency.