Caelum

Puppet. This creature's mind is not it's own. It makes any save against spells that try to influence the mind at advantage.

Spellcasting. [Caelum] is a 17-level spellcaster. Its spellcasting ability is [Wisdom] (spell save DC 19, +11 to hit with spell attacks). [Caelum] has following [Cleric] spells prepared: (replace radiant damage with necrotic at DM choice)
Cantrips (at will): [Toll the Dead], [Light], [Guidance], [Sacred Flame], [Word of Radiance] 
1st level (4 slots): [Guiding Blot], [Shield of Faith], [Bane], [Cure Wounds], [Detect Magic], [Healing Word], [Inflict Wounds]

2nd level (3 slots): [Magic Weapon], [Spiritual Weapon], [Aid], [Blindness/Deafness], [Enhance Ability], [Hold Person], [Silence]

3rd level (3 slots): [Crusader's Mantle], [Spirit Guardians], [Dispel Magic], [Glyph of Warding]

4th level (3 slots): [Fire Shield], [Freedom of Movement], [Death Ward], [Guardian of Faith]

5th level (2 slots): [Hold Monster], [Steel Wind Strike], [Flame Strike]

6th level (1 slot): [Harm], [Sunbeam]

7th level (1 slot): [Fire Storm]

8th level (1 slot):

9th level (1 slot): [Gate]

Spell Attack. Caelum casts a spell.

Mace. Melee Weapon Attack: +7 to hit, reach 5 ft., 1 target. Hit: 4 (1d6 + 1) [Bludgeoning] damage. 

normal bonus action rules.

War Caster Reaction. Caelum has the war caster feat.

At the end of any turn Caelum can use one of the following legendary actions. (3 per round)

Command Over Decay (Costs 2 Actions). Caelum calls upon the Queen of Decay to cast one of the following spells: False Life, Inflict Wounds, Vampiric Touch. Roll to determine the level the spell is cast at, for Vampiric Touch the spell is cast at 3rd level unless a 4 is rolled. [roll]1d4[/roll] (resource dependent)

Repentant Soul (Costs 3 Actions). 1d6 Recharge on 4-6. Caelum attempts to stir feelings of remorse in an enemy. Caelum can target any creature within 60ft. The enemy must make a Charisma saving throw DC19. If the target fails they are considered Charmed. on their turn they must attack the nearest enemy of Caelum. This condition lasts for 3 turns. The Charmed creature can repeat the save at the end of it's turn or upon taking damage. (This is considered a spell for the sake of counter spell)

Sapping Strike (Costs 1 Action). Caelum makes a mace attack empowered with negative energy. On hit the target takes the normal damage and must make a DC19 constitution saving throw. On a Fail the target has disadvantage on attack rolls on its next turn and takes 2d6+5. On a successful save the creature takes half the damage and does not receive disadvantage. 

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Mythic Action Name (Costs # Actions). Enter the description for your mythic action.