Astral Guardian

Immutable Form. The astral guardian is immune to any spell or effect that would alter its form.

Magic Resistance. The astral guardian has advantage on saving throws against spells and other magical effects.

 Magic Weapons. The astral guardian's weapon attacks are considered magical.

Astral Sight. The astral guardian can see into the Ethereal Plane within 60 feet of it.

Multiattack. The astral guardian makes two slam attacks.

 Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 5) bludgeoning damage.

Force Beam. Ranged Spell Attack: +6 to hit, range 60 ft., one target. Hit: 22 (4d10) force damage.

Astral Pulse (Recharge 5-6). The astral guardian releases a burst of energy in a 15-foot radius centered on itself. Each creature in that area must make a DC 16 Constitution saving throw, taking 35 (10d6) force damage on a failed save or half as much on a successful one.

Astral Resilience. When the astral guardian is targeted by a spell that requires a saving throw, it can use its reaction to gain advantage on the saving throw.

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

Force Swipe. The astral guardian makes one slam attack.

Astral Barrier (Costs 2 Actions). The astral guardian creates a protective barrier around itself, gaining temporary hit points equal to 2d8 + 5.

Astral Surge (Costs 3 Actions). The astral guardian releases a surge of astral energy, forcing all creatures within 10 feet of it to make a DC 16 Strength saving throw or be pushed back 10 feet and knocked prone.