Originally created for crusading holy champions, crusader helms have been in constant production for thousands of years. While only ancient helmets are considered relics, the magical properties of modern crusader helms match their archaic precursors. A crusader helm replaces a suit of armor’s normal helmet (if any) and is incorporated into the armor’s normal environmental protections; these protections do not function if the helm is removed. If the armor has an available upgrade slot, a crusader helm takes up one upgrade slot; otherwise, the helm counts as one of your two worn magic items.
While wearing a crusader helm, the first time each day that you attempt a saving throw against an enchantment or illusion effect created by an evil outsider, roll the saving throw twice and take the best result. You cannot gain the effects of more than one crusader helm each day.