Helm of Brilliance

This 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 the helm. a saving throw against a spell.

On a roll of 1, the helm emits beams of light from its remaining gems and is then destroyed.

Each creature within a 60-foot Emanation originating from you must succeed on a DC 17 Dexterity saving throw or be struck by a beam, taking Radiant damage equal to the number of gems in the helm.