Helm of Brilliance

A  is a headpiece set with many gems that provides the wearer with a number of different offensive and defensive abilities.

Appearance
A helm of brilliance is silver and embedded with many diamonds, rubies, fire opals, and regular opals.

Properties
The gems in a helm of brilliance can be removed and used to cast various spells. After the casting, the gem is destroyed; if all the gems from a helm of brilliance are removed, the helm itself ceases to be magical. If the person attuned to a helm of brilliance, while wearing it, takes fire damage as the result of a failed saving throw against a spell, they must roll a d20. On a natural 1, all the gems in the helm give off beams of radiant light, and all creatures within a 60 foot radius of the helm, other than the wearer, must succeed on a DC 17 Dexterity saving throw or take radiant damage equal to the number of gems that are still in the helm, as the helm self-destructs.
 * The diamonds in the helm can be used to cast the spell Prismatic Spray. Additionally, if the helm has at least one diamond in it, it will shed dim light when within 30 feet of an undead creature, and any undead who start their turn within the range of this light take 1d6 radiant damage.
 * The rubies in the helm can be used to cast the spell Wall of Fire. Additionally, if the helm has at least one ruby in it, the person attuned to the helm has resistance to fire damage.
 * The fire opals in the helm can be sed to cast the spell Fireball. Additionally, if the helm has at least one fire opal in it, the person attuned to it can, as an action, speak a command word causing one weapon they are holding to burst into flames. These flames are harmless to the wearer, but will deal 1d6 additional fire damage to anyone hit by the weapon.
 * The opals can be used to cast the spell Daylight.

History
Taryon Darrington had a helm of brilliance, which he owned already upon his first meeting with Vox Machina. He later worked with Percy to create lanterns that were powered by the opals of the helm. The helm also served Tary well in the Nine Hells, in which it helped him resist fire damage.

Trivia
Tary is depicted as wearing the helm in the advertisement for the Slayer's Cake.