Barachiel, the messenger

Indelible Imprint. When one of the celestial hebtomad is slain those who dealt damage to it within the last 24 hour and is within 60ft of the dying celestial hebtomad must make a dc 24 Wisdom save or be marked with a glowing rune on their forehead making any lawful good creature feel the need to murder as you have broke a grand divine law. 

Legendary Resistance (3/Day). If Barachiel fails a saving throw, he can choose to succeed instead.

Electrify Blade. Any metal weapon Barachiel wields or picks up becomes a magical lightning weapon that deals an extra 2d12 lightning damage with their attacks. Barachiel normally wields a metal long sword. If a weapon is taken off of Barachiel or if he is disarmed the effect on the weapon is gone as its not being held by Barachiel and all their attacks count as magical. 

Trumpet. Barachiel's trumpet always emits a very harmonious sound. Each creature who isn't an archon or celestial within 100ft must make a dc 19 Charisma save or be paralyzed with awe until the end of their next turn. If the trumpet is some how stolen  from Barachiel it turns into chunks of useless metal. Once a creature fails the save  and undergoes the effect they are immune to the effect for 1 hour and Barachiel can choose to turn the power off when they please. 

Aura of Menace. Whenever Barachiel is angry or fighting any hostile creature within a 20ft radius of Barachiel must make a dc 19 Charisma save or have disadvantage on attacking Barachiel for 24 hours or until the creature hits Barachiel. On a successful save a creature is immune to Barachiel's aura of menace for 24 hours.

Protection from evil. Barachiel is constantly under the effects of the spell protection from good and evil but it only effects evil creatures. 

Magic Resistance. Barachiel has advantage on saving throws against spells and other magical effects.

Spellcasting. Barachiel is a 20th-level spellcaster. Its spellcasting ability is Charisma(spell save DC 23, +15 to hit with spell attacks). Barachiel has following cleric spells prepared:
Cantrips (at will): guidance, light, mending, resistance, word of radiance  
1st level (4 slots): bless, command, sanctuary, shield of faith 
2nd level (3 slots): aid, blindness/deafness, zone of truth 
3rd level (3 slots): create food and water, daylight, magic circle
4th level (3 slots): death ward, freedom of movement, guardian of faith
5th level (3 slots): commune, geas, greater restoration 
6th level (2 slots): forbiddance, heal
7th  level (2 slots): fire storm, temple of the gods
8th level (1 slots): holy aura
9th level (1 slots): astral projection

Innate Spellcasting. Barachiel's innate spellcasting ability is Charisma (spell save DC 23). Barachiel can innately cast the following spells, requiring no material components:

At will: beacon of hope, blinding smite, ceremony, daylight, detect good and evil, dispel magic, dream, hallow, holy aura, lightning, message, power word stun, sacred flame, sending, shield of faith, teleport, true seeing, wall of light, word of radiance

1/day each: creation, true resurrection 

Lightning sword. Melee Weapon Attack: +9 to hit, reach 10 ft., 1 target. Hit: 9 (2d6 + 3) slashing damage plus 12 (2d12) lightning damage. 

Lightning stroke. As long as barachiel has a metal weapon in his hands he can use this attack. One creature of Barachiel's choice within 100ft must make a dc 19 dexterity saving throw or take 30 (10d6) lightning damage. Half damage if the creature makes a successful save. 

Summon Archon (2/Day). Barachiel can choose to summon one of the following options with a 25% failure rate. 

4d10 lantern archons, 2d4 justice archons, 2d4 sword archons, and has a 5% chance to summon 1 other member of the Hebdomad. 

A summoned archon appears in an unoccupied space within 60 feet of Barachiel, acts as an ally of Barachiel, and can’t summon other archons. It remains for 1 minute, until it or Barachiel dies, or until Barachiel dismisses it as an action.

Barachiel can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature’s turn. Barachiel regains spent legendary actions at the start of his turn.

Move (Costs 1 Actions). Barachiel flies 60ft without provoking attacks of opportunity and one creature that barachiel moves within 5ft of during the movement takes 6 (2d6) lightning damage. 

Lightning stroke (Costs 2 Actions). Barachiel uses their lightning stroke attack. 

Trumpet of goodness (Costs 3 Actions). Each non lawful good creature within 120ft of Barachiel that can hear them must make a dc 19 Charisma save or be frightened for 1d4 rounds.