Sources
CR
Type
Size
Alignment
Movement

Planar Incarnate

Gargantuan Celestial, Any alignment

Armor Class 20 (natural armor)
Hit Points 333 (18d20 + 144)
Speed 40 ft., fly 40 ft.
STR
27
+8
DEX
10
+0
CON
26
+8
INT
15
+2
WIS
20
+5
CHA
20
+5
Skills Perception +12
Damage Immunities necrotic, poison, radiant; bludgeoning, piercing, slashing, from nonmagical attacks
Condition Immunities Charmed, Exhaustion, Frightened, Grappled, Paralyzed, Petrified, Poisoned, Restrained, Stunned, Unconscious
Senses truesight 120 ft., passive Perception 22
Languages all
Challenge 22 (41,000 XP)

Traits

Legendary Resistance (3/Day). If the incarnate fails a saving throw, it can choose to succeed instead.

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

Planar Form. An incarnate on the Upper Planes is a Celestial. An incarnate on the Lower Planes is a Fiend.

Siege Monster. The incarnate deals double damage to objects and structures.

Actions

Multiattack. The incarnate makes two Slam or Energy Bolt attacks.

Slam. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit:27 (3d12 + 8) force damage.

Energy Bolt. Ranged Spell Attack: +12 to hit, range 120 ft., one target. Hit:32 (5d12) necrotic damage if the incarnate is a Fiend or radiant damage if the incarnate is a Celestial.

Planar Exhalation (Recharge 5–6). The incarnate exhales concentrated energy native to its plane in a 60-foot cone. Each creature in that area must make a DC 23 Constitution saving throw. On a failed save, a creature takes 52 (8d12) necrotic damage if the incarnate is a Fiend or radiant damage if the incarnate is a Celestial, and the creature has the blinded condition until the end of the incarnate's next turn. On a successful save, a creature takes half as much damage only.

Reactions

Searing Gaze. In response to being hit by an attack roll, the incarnate turns its magical gaze toward one creature it can see within 120 feet of itself and commands it to combust. The target must succeed on a DC 20 Wisdom saving throw or take 16 (3d10) fire damage.

Teleport. Immediately after a creature the incarnate sees ends its turn, the incarnate teleports up to 60 feet to an unoccupied space it can see.

Lore

The Upper and Lower Planes are fundamental manifestations of good and evil, law and chaos. In the most dire and fateful circumstances, these planes can manifest primal embodiments of their might. These expressions of a plane's power are called planar incarnates, and they appear as roiling energies with features distinct to the plane that created it. They protect their home from destructive or otherwise antithetical forces, then merge back into their plane of origin.