Eldritch Mind. The cultist has advantage on Constitution saving throws to maintain concentration on a spell.

Spellcasting. The fanatic is a 9th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 11, +3 to hit with spell attacks). The fanatic has the following cleric spells prepared:

At-will: booming blade, eldritch blast, mage armor, prestidigitation

2/rest: darkness, dispel magic, hex, hold person, mirror image, fireball

Multiattack. The cultist attacks twice with its daggers or twice with its Eldritch Blast.

Dagger. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one creature. Hit: 5 (1d4 + 3) piercing damage.

Eldritch Blast. Ranged Spell Attack: +7 to hit, range 120 ft., one creature. Hit: 9 (1d10 + 4) force damage. The warlock can also push the target up to 10 ft. away in a straight line.