This dazzling helm is set with 1d10 diamonds, 2d10 rubies, 3d10 fire opals, and 4d10 opals. Any gem pried from the helm crumbles to dust. When all the gems are removed or destroyed, the helm loses its magic. You gain the following benefits while wearing it: You can use an action to cast one of the following spells (save DC 18), using one of the helm's gems of the specified type as a component: daylight (opal), fireball (fire opal), prismatic spray (diamond), or wall of fire (ruby). The gem is destroyed when the spell is cast and disappears from the helm. As long as it has at least one diamond, the helm emits dim light in a 30-foot radius when at least one undead is within that area. Any undead that starts its turn in that area takes 1d6 radiant damage. As long as it has at least one ruby, you have resistance to fire damage. As long as it has at least one fire opal, you can use an action and speak a command word to cause one weapon you are holding to burst into flames for 10 minutes (1d6 fire damage on hit).