Clerics of Lesser Powers

Worshipping Lesser Powers
Apparently, creatures of high power who are less than divine can be worshipped and they can grant clerical spells to their followers. Volo's Guide to Monsters has the Kraken Priest NPC, which is a Cleric, not a Warlock or other Arcane spell caster. So taking that as a minimum standard, then creatures such as Archfiends and Archfey could have priests who worship them and gain spells. Using the Kraken Priest as an example, they may be limited to 8th level cleric and 4th level spells as a maximum. Using warlocks as an inspiration, here are some examples.

Priest of the Archdemon
1st level- Heavy armor proficiency and learn Firebolt cantrip.
Bonus Spells
Level Spells
1st Burning Hands, Command
2nd Blindness/Deafness, Scorching Ray
3rd Fireball, Stinking Cloud
4th Fire Shield, Wall of Fire
2nd level- Channel Divinity, Cause Fear? Resist Fire?
6th level-
8th level- Divine Strike is Fire damage

Priest of the Archdevil
1st level- Heavy armor and Martial weapons proficiency.
Bonus Spells
Level Spells
1st Burning Hands, Command
2nd Blindness/Deafness, Scorching Ray
3rd Fireball, Stinking Cloud
4th Fire Shield, Wall of Fire
2nd level- Channel Divinity, Hold Person? Resist Fire?
6th-
8th level- Divine Strike is Fire damage

Priest of the Archfey
1st level- Martial weapon proficiency and learn Frostbite cantrip for Winter Fey, Firebolt cantrip for Summer Fey.
Bonus Spells
Level Spells
1st Faerie Fire, Sleep
2nd Calm Emotions, Phantasmal Force
3rd Blink, Plant Growth
4th Dominate Beast, Greater Invisibility
2nd level- Channel Divinity, Charm Person
6th level- Misty Escape
8th level- Divine Strike is Cold damage for Winter Fey, Fire for Summer Fey

Priest of the Celestial
1st level- Martial weapons proficiency and learn Word of Radiance cantrip.
Bonus Spells
Level Spells
1st Cure Wounds, Guiding Bolt
2nd Flaming Sphere, Lesser Restoration
3rd Daylight, Revivify
4th Guardian of Faith, Wall of Fire
2nd level- Channel Divinity,
6th level- Radiant Soul, add Wisdom bonus to one damage roll doing Fire or Radiant damage
8th level- Divine Strike is Radiant damage

Priest of the Old Ones
1st level- Heavy armor proficiency and learn Mind Sliver cantrip.
Bonus Spells
Level Spells
1st Arms of Hadar, Dissonant Whispers
2nd Crown of Madness, Phantasmal Force
3rd Hunger of Hadar, Animate Dead (Enemies Abound?)
4th Dominate Beast, Evard's Black Tentacles (Raulothim's Psychic Lance?)
2nd level- Channel Divinity: Temporary Insanity- Confusion spell for one round
6th level- Twist Fate- Use reaction roll to impose disadvantage on enemy's attack. If they miss, you gain advantage on your next attack.
8th level- Divine Strike is Psychic damage

Priest of the Kraken
1st level- Martial weapons proficiency and learn Shocking Grasp cantrip.
Bonus Spells
Level Spells
1st Command, Create/Destroy Water
2nd Darkness, Summon Beast (water only)
3rd Water Breathing, Call Lightning
4th Evard's Black Tentacles, Control Water
2nd level- Channel Divinity, Cause Fear
6th level- Thunderwave?
8th level- Divine Strike is Cold (Poison?) damage

Give demons more chaos, give devils more fire?