Dark Devotion. The fanatic has advantage on saving throws against being charmed or frightened.

Spellcasting. The fanatic is a 4th-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: dancing lights, chill touch, thaumaturgy

2/day each: false life, hellish rebuke, hold person, inflict wounds

Multiattack. The fanatic makes two melee attacks.

Morningstar. Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one creature. Hit: 7 (1d8 + 2) piercing damage.

Embrace the Pain. At the start of its turn, the fanatic can gain advantage on all melee attack rolls it makes during that turn, but attack rolls against it have advantage until the start of its next turn.

Share the Pain. After suffering a critical hit, the cultist can make one melee attack with advantage as a reaction.