Celestial Sight.
Magical darkness doesn’t impede Zariel’s darkvision.

Divine Awareness.
Zariel knows if she hears a lie. 

Angelic Weapons.
Zariel’s weapon attacks are magical. When she hits with any weapon, the weapon deals an extra 36 (8d8) fire damage (included in the weapon attacks below).

Innate Spellcasting.
Zariel’s innate spellcasting ability is Charisma (spell save DC 26). She can innately cast the following spells, requiring no material components:

At will: Alter Self (can become Medium when changing her appearance), Detect Evil and Good, Invisibility (self only)

3/day each: Blade Barrier, Dispel Evil and Good, Resurrection

1/day each: Commune, Control Weather

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

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

Multiattack. Zariel makes three attacks with the Sword of Zariel. She can substitute one of these attacks to use either Healing Touch or a Celestial Smite. 

Sword of Zariel. Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 18 (2d8 + 8) slashing damage or 20 (2d10 + 8) slashing damage if you're wielding the weapon with two hands plus 20 (4d8)  radiant damage or 40 (8d8)  radiant damage if you're wielding the weapon with two hands. An evil creature struck by this weapon must succeed a DC 17 Constitution saving throw or be blinded until the end of its next turn.

Celestial Smite. Ranged Spell Attack: +16 to hit, range 120 ft., one target. Hit: 40 (8d8) radiant damage. If the target is an evil creature that has 100 hit points or fewer, it must succeed on a DC 26 Constitution saving throw or die. A creature killed by this attack has its body disintegrated.

Healing Touch (4/Day). Zariel touches another creature. The target magically regains 40 (8d8 + 4) hit points and is freed from any curse, disease, poison, blindness, or deafness. An undead or fiend type creature that is not good aligned touched by this ability must succeed a DC 26 Constitution saving throw, or suffer the same amount of radiant damage, instead of healing.

Teleport. Zariel magically teleports, along with any equipment she is wearing or carrying, up to 120 feet to an unoccupied space she can see.

Zariel 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. Zariel regains spent legendary actions at the start of her turn.

Teleport. Zariel uses her Teleport action.

Searing Burst (Costs 2 Actions). Zariel emits magical, divine energy. Each creature of her choice in a 10 foot radius must make a DC 23 Dexterity saving throw, taking 14 (4d6) fire damage plus 14 (4d6) radiant damage on a failed save, or half as much damage on a successful one. 

Blinding Gaze (Costs 3 Actions). Zariel targets one creature she can see within 30 ft. of her. If the target can see her, the target must succeed on a DC 15 Constitution saving throw or be blinded until magic such as the Lesser Restoration spell removes the blindness.