Although potent and heavily armed the Xiphon was both more complex and had a limited operational range when compared to the larger Wrath Starfighter as well as being ill-favoured by the Mechanicum. The Xiphon fell out of use by most of the Space Marine Legions by the end of the Great Crusade, with only the Ultramarines and Dark Angels Legions continuing to use them in frontline service. Once the Horus Heresy began, the exigencies of combat and a shortage of replacements for the Imperium's preferred aircraft led many Legions to press their reserves of Xiphons back into battle.