Astral Enigma

Ethereal Form. The alien can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Energy Field Manipulation. As a bonus action, the alien can manipulate its energy field to assume a humanoid shape or produce human-like speech. The mimicry of human speech is convincing but limited, primarily used for basic communication.

Telepathic Bond. The alien can communicate telepathically with any creature it can see within 120 feet. The telepathic bond allows the exchange of thoughts, emotions, and memories.

Chaotic Anomaly. The alien exists in a state of constant flux, granting it advantage on all saving throws against spells or effects that would alter its form or mind.

Spellcasting. The alien is a 9th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 18, +10 to hit with spell attacks). The alien has the following spells prepared:

Cantrips (at will): Mage Hand, Minor Illusion, Prestidigitation

1st level (4 slots): Command, Disguise Self, Hold Person

2nd level (3 slots): Calm Emotions, Detect Thoughts

3rd level (3 slots): Counterspell, Tongues

4th level (3 slots): Dimension Door, Phantasmal Killer

5th level (2 slots): Dominate Person, Mislead

Energy Blast. Ranged Spell Attack: +8 to hit, range 120 ft., one target. Hit: 36 (8d8) force damage. The target must succeed on a DC 16 Strength saving throw or be pushed back 20 feet and knocked prone.

Luminous Touch. Melee Spell Attack: +8 to hit, reach 5 ft., one target. Hit: 22 (4d8 + 4) radiant damage, and the target must succeed on a DC 16 Wisdom saving throw or be blinded until the end of its next turn.

Astral Displacement (Recharge 5-6). The alien targets itself and disappears from its current location, reappearing up to 120 feet away in a space it can see. Any creature occupying that space must succeed on a DC 16 Dexterity saving throw or take 33 (6d10) force damage as the alien's energy field forcibly displaces them 5 feet in a random direction.

Cosmic Pulse (Costs 1 Bonus Action). The Astral Enigma releases a powerful surge of cosmic energy in a 10-foot radius around itself. Each creature within this area must make a DC 16 Constitution saving throw. On a failed save, the creature takes 1d4 force damage and is stunned until the end of its next turn. On a successful save, the creature takes half damage and isn't stunned.

Reactive Teleport. If the alien is targeted by an attack it can see, it can use its reaction to teleport up to 30 feet to an unoccupied space it can see. The attack misses, and the alien's visibility is obscured until the start of its next turn.

The alien can take three 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 alien regains spent legendary actions at the start of its turn.

Energy Burst. The alien releases a burst of energy in a 20-foot radius centered on itself. Each creature in that area must make a DC 16 Dexterity saving throw, taking 28 (8d6) force damage on a failed save or half as much on a successful one.

Telepathic Probing. The alien targets one creature it can see within 60 feet and attempts to probe its thoughts. The target must succeed on a DC 16 Wisdom saving throw or become charmed by the alien for 1 minute, unable to take reactions and regarding the alien as a trusted friend.

Ethereal Shift (Costs 2 Actions). The alien shifts partially into the ethereal plane for up to 3 rounds. While shifted, it gains immunity to all damage except force damage. It can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object. At the end of the 3rd round, the alien reverts to its normal form.