Celestial Golem

Elemental Engine. The Celestial Golem powers itself by cycling through intaking and exhausting elemental powers. At the beginning of the Celestial Golems turn, roll a D6 to determine which elemental power is currently powering the Engine. See the table below for the results of each roll and the corresponding effect:

1. Radiant - The golem glows yellow and is immune to Radiant damage and is healed half the amount of any radiant damage done to the golem while it is powered in this form. Correspondingly, the golem becomes vulnerable to necrotic damage.
2. Fire - The golem glows red and is immune to Fire damage and if hit by fire damage, it reflects half of the damage back at the attacker, or if an area of effect fire damage is caused, it does half the area of effect damage in a 10 foot radius around itself. The golem becomes vulnerable to cold damage.
3. Cold - The golem glows blue and is immune to Cold damage and if hit by cold damage, it sends freezing energy back at the source of the damage. The affected creature must make a DC 17 Constitution saving throw or be paralyzed for 1 minute. The creature can repeat the saving throw at the end of its subsequent turns. The golem becomes vulnerable to lightning damage.
4. Thunder or Force - The golem glows white and is immune to force and thunder damage and if hit by thunder of force damage, every creature in a 10 ft radius centered around the golem must make a DC 17 Strength saving throw or be thrown back 10 feet. The golem becomes vulnerable to slashing, piercing and bludgeoning damage.
5. Bludgeoning, slashing and piercing damage - The golem rolls up into a hardened ball, becoming immune to bludgeoning, slashing and piercing damage and if struck by damage of this type, the creature who caused the damage must make a DC 17 Wisdom saving throw or become blinded and deafened until the end of the creature's next turn in a flash of psychic energy. The golem becomes vulnerable to acid damage.
6. Cloaked - The golem becomes invisible while in this state.

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

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

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

Elemental Abilities (Recharge 3-6). Depending on Elemental Engine roll for the current turn, the golem can make the corresponding actions:

1. Multiattack - The golem can make two Radiant Lance attacks.
   
   • Radiant Lance- Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 19 (3d8+6) radiant damage.
2. Fire Cannon - The golem shoots a small ball of flame from a floating, fiery magic cannon at a point. Each creature in a 10-foot-radius sphere centered on that point must make a DC 17 Dexterity saving throw. A target takes 6d6 fire damage on a failed save, or half as much damage on a successful one. The fire spreads around corners. It ignites flammable objects in the area that aren't being worn or carried.
3. Cold Burst - The golem fires frozen shards of ice from it's core. Each creature in a 45 ft cone must make a DC 17 Constitution saving throw. A creature takes 5d8 cold damage on a failed save, or half as much damage on a successful one. A creature killed by this spell becomes a frozen statue until it thaws.
4. Concussive Force - The golem resonates from within, creating a concussive wave and a crack of thunder centered on the golem. Each creature within 15 feet of the golem must make a DC 17 Constitution saving throw or be stunned until the end of their next turn.
5. Psychic Intrusion - The golem chooses one creature within 10 ft of it and forces them to make a DC 17 Charisma saving throw or become charmed by the golem until the end of the creature's next turn. On a failed save, the golem can give one short command to the chosen creature, and the affected creature must obey that order to the best of their ability on their next turn. The creature cannot be made to hurt itself, though it can be made to attack its allies. This command is given in celestial, but the target does not need to understand celestial to be affected.
6. Shadow bolts - The golem makes two ranged Shadow Bolt attacks. It has advantage on these attacks if the golem currently can't be seen by the attacked creature.
   • Shadow Bolts. Ranged Weapon Attack: +10 to hit, reach 60 ft., one target. Hit: 15 (2d8+6) necrotic damage.

The celestial golem 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 celestial golem regains spent legendary actions at the start of its next turn.

Elemental Reset. The celestial golem rolls a d6 and the elemental cannon and abilities reset accordingly.