Source: Mythic Odysseys of Theros

Wondrous item, rare (requires attunement)

While wearing this helm, you know whether there is a celestial or fiend within 30 feet of you, as well as where the creature is located, provided the creature isn't behind total cover.

Whenever you finish a long rest while wearing the helm, you can pray to one of the gods listed on the Helm of the Gods table and store the listed spell in the helm, replacing any spell that is already stored there. The save DC for the spell is 13.

The helm has 3 charges. To cast a spell from the helm, you must expend 1 charge, and the helm regains 1d3 charges daily at dawn.

Helm of the Gods
God Spell
Athreos Protection from Evil and Good
Ephara Sanctuary
Erebos Inflict Wounds
Heliod Guiding Bolt
Iroas Heroism
Karametra Goodberry
Keranos Thunderous Smite
Klothys Entangle
Kruphix Dissonant Whispers
Mogis Hellish Rebuke
Nylea Faerie Fire
Pharika Lesser Restoration
Phenax Charm Person
Purphoros Searing Smite
Thassa Identify