Azrakia

He is what you expect of "divine intervention". He is Azrak's mortal form, despite technically being a separate entity.

Azrakia, The Eternal One
Medium humanoid (human), lawful good (divine essence)

Armor Class 30 (Divine Aura + Celestial Shield)
Hit Points 1 (but cannot take damage unless it is from a being they deem "truly good")
Speed 60 ft.

STR 30 (+10)
DEX 30 (+10)
CON 30 (+10)
INT 30 (+10)
WIS 30 (+10)
CHA 30 (+10)

Saving Throws All +20
Skills All +20
Damage Resistances All damage types
Senses Truesight 120 ft., Passive Perception 30
Languages All languages, telepathic communication with any creature

Challenge 100 (10,000,000 XP) will not give exp upon defeat due to immortal nature

Traits

Omniscient Magic. The Eternal One has access to all spells from all spell lists, including those normally unavailable to their race or class, and can cast them without expending spell slots. They can cast each spell an unlimited number of times, and all spells cast have no verbal, somatic, or material components.

Instantaneous Casting. All magic used by the Eternal One takes effect immediately, with no casting time, reaction time, or verbal/somatic components required. They may cast spells as a bonus action or reaction, regardless of the spell's original casting time.

Perfect Immunity. The Eternal One is immune to all forms of damage, conditions, poisons, diseases, and magical effects, including those that normally bypass resistance. They are immune to aging, fatigue, and death (except under specific conditions described below).

Divine Essence. The Eternal One is an immortal being whose existence is tied to a divine realm. They are immune to all death effects, and any damage they receive is ignored unless it comes from a being the Eternal One deems "truly good." When a creature with this quality causes damage, the Eternal One can choose to return to the divine realm, healing to full hit points and becoming untouchable for 1 hour. During this time, no creature can harm the Eternal One.

Unyielding Will. The Eternal One cannot be mentally affected, charmed, or frightened by any force. They automatically succeed on saving throws against any effect that would influence their mind.

No Need for Sustenance. The Eternal One does not need to eat, drink, sleep, or breathe and is unaffected by environmental conditions such as extreme heat, cold, high altitude, or underwater.

Eternal Vigilance. The Eternal One has perfect awareness of their surroundings and can see and hear everything within a 1-mile radius. They can also perceive events across time as though watching them unfold in real-time, provided the events are not shielded from divine sight.

Actions

Trait: Cannot harm the innocent, or those who are "truly good" (almost no-one in this case)

Omni Strike (Melee Weapon Attack):
Weapon Attack: +20 to hit, reach 10 ft., one target.
Hit: 50 (10d10 + 10) force damage. The Eternal One can choose to add 25 radiant damage if the target is evil or corrupt.

Divine Reckoning (Recharge 5-6). The Eternal One unleashes a divine burst in a 200-foot radius. All creatures within this radius must make a DC 30 Constitution saving throw, taking 100 (20d10) radiant damage and being knocked prone on a failed save, or half as much damage on a successful save. The Eternal One can also choose to heal all creatures within range for 50 hit points instead.

Reality-Warping Power (1/Day). The Eternal One can reshape the fabric of reality itself in a 100-foot cube. All creatures within the area must make a DC 30 Wisdom saving throw or be banished to an alternate dimension of the Eternal One's choosing for 1 minute. Creatures who succeed are immune to this effect for 24 hours.

Legendary Actions

The Eternal One 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. The Eternal One regains spent legendary actions at the start of their turn.

Divine Intervention. The Eternal One automatically counters any spell or attack directed at them, nullifying its effect completely.

Time-Locked (Costs 2 Actions). The Eternal One can freeze time for all creatures within a 100-foot radius for 1 round, except for themselves and their allies. During this time, they can take actions freely.

Perfect Heal (Costs 2 Actions). The Eternal One can fully heal any creature they can touch, restoring all hit points and curing any diseases, poisons, or curses.

Reactions

Divine Rebirth. If the Eternal One is reduced to 0 hit points by a being they do not deem "truly good," they immediately heal to full hit points and are immune to all damage for the next 24 hours. If they are reduced to 0 hit points by a being they consider "truly good," they return to the divine realm and cannot be harmed for 1 hour.

Unstoppable Defense. When the Eternal One is hit by an attack, they can use their reaction to cause the attack to miss entirely and immediately teleport to any unoccupied space within 300 feet.

Spellcasting

The Eternal One can cast any spell from any source (arcane, divine, or otherwise) with no spell slots, no material components, and no limitations. They can also cast these spells instantaneously with perfect mastery over all magic. Some sample spells (and their effects) include:

Cantrips (at will): All cantrips available from any class or school of magic, all cast instantaneously
1st level (at will): Cure Wounds, Magic Missile, Shield, Identify
2nd level (at will): Misty Step, Mirror Image, Counterspell, Hold Person
3rd level (at will): Fireball, Counterspell, Dispel Magic, Fly
4th level (at will): Greater Invisibility, Dimension Door, Polymorph
5th level (at will): Wall of Force, Teleportation Circle, Animate Objects
6th level (at will): True Seeing, Chain Lightning, Heal
7th level (at will): Plane Shift, Fire Storm, Resurrection
8th level (at will): Power Word Stun, Clone, Dominate Monster
9th level (at will): Wish, Meteor Swarm, Time Stop

Legendary Resistance (Unlimited)

The Eternal One automatically succeeds on all saving throws against magical or physical effects that would otherwise affect them.

Special Mechanics

"Truly Good" Definition: The Eternal One deems a being "truly good" based on their purity of heart, selflessness, and divine essence. These beings are typically celestial or entities of a similarly pure and altruistic nature, including certain deities or celestial beings. If such a being damages the Eternal One or attempts to harm them, the Eternal One can react by returning to the divine realm, effectively "retiring" from the material plane for a short period (1 hour).