Astral Unicorn

Magic Resistance. The Astral Unicorn has Advantage on saving throws against spells and other magical effects.

Multiattack. The Astral Unicorn makes two attacks with Hooves or Radiant Horn in any combination. It can replace one of these attacks with Spellcasting or Astral Pulse (if available).

Hooves. Melee Attack Roll: +8, reach 5 ft. Hit: 14 (2d8 + 5) Bludgeoning damage. 

Radiant Horn. Melee Attack Roll: +8, reach 5 ft. Hit: 11 (1d10 + 5) Radiant or Force damage. If the Astral Unicorn moves at least 30 feet straight toward a target and then hits it with a Radiant Horn attack on the same turn, the target takes an extra 9 (2d8) Radiant or Force damage. If the target is a creature, it must succeed on a DC 16 Strength saving throw or be knocked prone. 

Spellcasting. The Astral Unicorn casts one of the following spells, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 16):

At Will: Detect Evil and Good, Druidcraft, Remove Curse
1/Day Each: Calm Emotions, Dispel Evil and Good, Entangle, Pass without Trace, Word of Recall, Beacon of Hope 

Astral Pulse (Recharge 4-6). The Astral Unicorn releases a wave of astral energy in a 30-foot radius around itself. Each creature of its choice in that area must make a DC 16 Wisdom saving throw or take 36 (8d6) Psychic damage and be Stunned until the start of the Astral Unicorn's next turn. 

Unicorn’s Blessing (3/Day Each). The Astral Unicorn touches another creature with its horn and casts Healing Word, Mass Healing Word, Sanctuary, or Lesser Restoration on that creature, using the same spellcasting ability as Spellcasting.

Shimmering Shield. When the Astral Unicorn or an ally it can see within 60 feet of itself is hit with an attack roll, the target gains 14 (4d6) Temporary Hit Points, and its AC increases by 2 until the end of the Astral Unicorn’s next turn. If the target already has Temporary Hit Points, the target heals for that amount instead.