Aether Whale

Echolocation. The whale can't use its blindsight while deafened.

Celestial Breath. The whale doesn't need to breathe, but can provide breathable air to creatures within 15 feet of it.

Divine Passing. Creatures the whale trusts are granted a flying speed equal to that of the whales. If the whale is carrying passengers on its back, the whale can carry those creatures with it when it planeshifts.

Keen Hearing. The whale has advantage on Wisdom (Perception) checks that rely on hearing.

Magic Weapons. The whale's weapon attacks are magical.

Innate Spellcasting. The whale's spellcasting ability is Wisdom (spell save DC 15). It can innately cast the following spells, requiring no components:

At will: Detect Evil and Good, Bless, Light, Fly

3/day each: Cure Wounds(second level), Lesser Restoration, Sanctuary, Fog Cloud

1/day each: Planeshift (self only, unless carrying passengers it trusts), Daylight

Bite. Melee Weapon Attack:  +8 to hit, reach 5 ft., one target. Hit: 21 (5d6 + 4) piercing damage.

Wings. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit 12 (2d8 + 4) bludgeoning damage.

Call Out (recharge 5-6). The whale releases a cry, causing one of the following d6 of sounds.

1. Church Bells. Evil creatures within 60 ft. must succeed a DC 15 Wisdom save, or take 6 (2d6) Radiant damage, or half as much on a successful save.
2. Mystical Choir. Creatures within 60 ft. that the whale can see must succeed a DC 15 Constitution saving throw or take 11 (2d8 + 3) thunder damage.
3. Reverberating Chimes. The whale regains any damage dealt to it on the previous turn as temporary hit points.
4. Doleful Cry. All creatures within 10 ft. of the whale must succeed a DC 15 Strength saving throws or be blasted 30 ft. away from the whale and take 16 (2d12 + 4) thunder damage.
5. Radiant Cheers. Creatures within 60 ft. of the whale must succeed a DC 15 Constitution saving throw or be blinded for 1 minute. A creature blinded this way can repeat the saving throw at the end of its turn, ending the effect on a success.
6. Wrathful Crashing. Ranged Spell Attack: +6 to hit, range 120 ft., one target. Hit: 19 (4d8 + 3) lightning damage.

The whale 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 whale regains spent legendary actions at the start of its turn.

Move. The whale moves up to its movement speed without provoking an attack of opportunity.

Radiant Hymn (costs 2 actions). The Whale bellows a beautiful noise, healing good aligned creatures for 20 hit points, and damaging evil aligned creatures for 20 points of necrotic, if they fail a DC 15 Wisdom saving throw. Neutral aligned creatures are unaffected by this ability.

Dispel Magic. The whale dispels a spell which has a harmful affect within 120 ft.