Aspect of Lucifer

Divine Awareness. Lucifer can perceive events anywhere in existence, knows the name and history of all creatures, and knows if he hears a lie.

Divine Resistance. Lucifer automatically gets the maximum result on D20 tests and damage rolls. Roll a D20 for attack rolls (with Advantage) to check for critical hits. Without his permission, spells or effects can't control Lucifer’s mind or actions, read his thoughts, remotely observe him, gather information about him, or alter his form or statistics.

Divine Restoration. If Lucifer dies, his body disappears, and he gains a new body instantly, reviving with all its Hit Points on the plane of his choice.

Psychopomp. A creature killed by Lucifer can only be restored to life by Lucifer and he controls the destination of its soul.

Multiattack. Lucifer makes four attacks, using Flying Sword and Lightbringer Bolt in any combination. He can replace one attack with a use of Overwhelming Presence or Spellcasting. 

Flying Sword. Melee or Ranged Attack Roll: +20 (with Advantage), reach 10 ft. or range 120 ft. Hit: 34 (4d6 + 10) Force damage plus 80 (10d8) Radiant damage that bypasses Resistance or Immunity. Hit or Miss: The sword magically returns to Lucifer’s hand or hovers within 5 feet of Lucifer immediately after a ranged attack.

Lightbringer Bolt. Ranged Attack Roll: +20 to hit (with Advantage), range 600 ft. Hit: If the target is a creature that has 100 Hit Points or fewer, it dies. It otherwise takes 80 (10d8) Radiant damage.

Overwhelming Presence. Each creature of Lucifer’s choice in a 60-foot Emanation that can see him is Frightened until the end of its next turn. Each Frightened creature in the area takes 100 (10d10) Psychic damage.

Spellcasting. Lucifer casts one of the following spells, as an action, requiring no spell components and no Concentration to maintain the spell, and using Charisma as the spellcasting ability (spell save DC 30):
At will: any spell of 9th level or lower (level 9 version); typically Fireball, Flame Strike, Hold Monster, Sunburst

Alter Reality (Recharge 6). Lucifer reshapes reality similar to the Wish spell without suffering stress or other limitations.

Divine Aid. Lucifer casts Greater Invisibility, Greater Restoration, Mass Heal, Power Word Fortify, Power Word Heal, Remove Curse, or Time Stop requiring no spell components and using the same spellcasting ability as Spellcasting.

Parry Spell. Trigger: Lucifer is targeted by a spell. Response: The spell has no effect and is reflected back at the spellcaster, using the slot level, spell save DC, attack bonus, and spellcasting ability of the caster.

Legendary Action Uses: 3. Immediately after another creature’s turn, Lucifer can expend a use to take one of the following actions. Lucifer regains all expended uses at the start of each of its turns.

Exalted Magic. Lucifer casts Fireball (level 9 version), Hold Monster (level 9 version), or Sunburst using Spellcasting.

Radiant Teleport. Lucifer teleports up to 120 feet to an unoccupied space he can see. Dexterity Saving Throw: DC 30, each creature in a 10-foot Emanation originating from Lucifer at his destination space. Failure: 22 (4d10) Radiant damage. Success: Half damage.

Smite. Lucifer moves up to half his speed without provoking opportunity attacks and makes one Flying Sword or Lightbringer Bolt attack.