Cult ArchBishop

Key of Prophecy. The Cult ArchBishop can always act in a surprise round, but if he fails to notice a foe, he is still considered surprised until he takes an action. He receives a +5 bonus on initiative checks.

Innate Spellcasting. The Cult ArchBishop innate spellcasting ability is Wisdom (spell save DC 17). He can innately cast the following spells, requiring no material components:

3/day each: detect thoughts, dimension door, haste, slow

2/day each: suggestion, teleport

1/day each:

Spellcasting: The Cult ArchBishop is a 15th-level spellcaster. His spellcasting ability is Wisdom (spell save DC 19, +10 to hit with spell attacks). The cult leader has the following cleric spells prepared:

Cantrips (at will): guidance, light, sacred flame, spare the dying, thaumaturgy
1st level (4 slots): cure wounds, inflict wounds, guiding bolt

2nd level (3 slots): silence, spiritual weapon, hold person

3rd level (3 slots): dispel magic, mass healing word, spirit guardians

4th level (3 slots): banishment, Freedom of Movement, guardian of faith

5th level (2 slots): flame strike, summon celestial

6th level (1 slot): harm

7th level (1 slot): Fire Storm

8th level (1slot): Holy Aura

Multiattack. The Cult ArchBishop can either make one melee attack and cast a cantrip or use a spell and a cantrip.

Mace. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 5 (1d6)+2 bludgeoning damage. 

Esoteric Vengence. As a reaction when struck by a melee attack, the Cult ArchBishop can expend a spell slot to do 10 (5d6) necrotic damage to the attacker. If the ArchBishop expends a spell slot of 2nd level or higher, the damage increases by 1d6 for each level above 1st.