Helm of Brilliance
Wondrous item, very rare, requires attunement · 2014 rules, SRD 5.1
Set with gems: cast daylight, fireball (DC 18), prismatic spray or wall of fire by spending a gem; sheds light; resistance to fire; undead take 1d6 radiant near you.
Also in the 2024 rules (SRD 5.2).