Fiendish Restoration. If it dies, the naga returns to life in 1d6 days and regains all its Hit Points. Only a Wish spell can prevent this trait from functioning.
Multiattack. The naga makes three attacks, using Bite or Necrotic Ray in any combination.
Bite. Melee Attack Roll: +7, reach 10 ft. Hit: 7 (1d6 + 4) Piercing damage plus 14 (4d6) Poison damage.
Necrotic Ray. Ranged Attack Roll: +6, range 60 ft. Hit: 21 (6d6) Necrotic damage.
Spellcasting. The naga casts one of the following spells, requiring no Somatic or Material components and using Intelligence as the spellcasting ability (spell save DC 14):
At Will: Detect Magic, Mage Hand, Minor Illusion, Water Breathing