New artifact Staff of Agni, a quarterstaff with the following fire-based properties:

• Can be zapped if its enchantment is positive for the same effect as casting a spell of fireball.
• Invoking it sets its enchantment to 3 + your skill in attack spells. (No effect if the enchantment is already higher than this.)
• Grants fire resistance when wielded.
• Deals double fire damage in melee like Fire Brand.
• Acts like a robe for reducing spellcasting failure, but only for the spell of fireball (and fire storm, if that is a separate spell).