Infernal Armor

Even though the name of the spell Infernal Armour suggests an armour made of flames, it is actually used to protect the caster from fire damage, may it be from natural fires, magical fire attacks or even from lava. Thus it is not an active attack spell, but the protection is nonetheless highly useful. However, this spell constantly feeds of the mage's mana until dismissed. Should mana run out while walking through lava...

Trivia

 * In Ultima IX, the white potion does have the same effect as the spell.