Large Fire sphinx, Chaotic Neutral
First Impression: A massive lioness carved of volcanic black rock sits imperiously on its haunches. Two black, folded, stone wings are frame either side and atop its head a pair of sweeping horns, stretch seven feet out to a before curving to a point like a great crown. The craftsmanship of its form is so life-like, you wonder if its stone appearance is simply some trick of the light. Suddenly it moves, small cracks in the seams of its joints, along curvature of its muscles appear facilitating motion. They glow molten orange, illuminating every detail of its form. The beast's eyes flare and a third eye appears on the ridges of its forehead. They stare at you, animal yet intelligent, then suddenly mortal, then suddenly wrong; too mortal, too divine, too something. A light rises from within its jaws, illuminating a mouth filled with obsidian daggered teeth and you hear it speak with three voices; female, grating, and all too knowing. True Form: Irninür's body jerks, twisting down with the harsh sound of rocks falling from a cliff. Her black basalt exterior cracks, slabs of stone crumbling to the floor, revealing muscles of molten magma beneath. White, orange, and red flames erupt from her crown, cascading into a billowing mane of fire and writhing smoke. Glowing sockets appear along her chest as two lithe arms of molten sinew and feline claws reach forward and twich to life. Her limbs bend and snap unnaturally, the joints deranged and wrong. The seams on the sides of her neck open, spilling lava and liquid shadow below as two skeletal heads wriggle out from the gap. Terrible pin-pricks of light flare in their empty sockets darting about; mad, gleeful, and bloodthirsty.
Irninür is the guardian of the Heart Hearth, the Cosmic Pillar that anchors the Plane of Fire to the Material Plane.
Charge: If Irninür moves at least 20 ft. straight toward a target and then hits it with her gore attack on the same turn, the target takes an additional 2d8 bludgeoning damage. If the target is a creature, it must succeed on a DC 15 Strength saving throw or be knocked prone. Inscrutable: Irninür is immune to any effect that would sense her emotions or ead her thoughts, as well as any divination spell that she refuses. Wisdom (Insight) checks made to ascertain Irninür's intentions or sincerity have disadvantage. Magic Weapons: Irninür's weapon attacks are magical. Two Forms: When Irninür falls below half health, her form changes to her Triptych Flame form. Additionally, she gains the following changes to her stats:
Multiattack: Irninür makes two claw attacks or one claw and one gore attack. Claw: Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 2d8+4 slashing damage. The target must also succeed on a DC 15 Constitution saving throw. On a failure, the target takes 3d6 fire damage or half as much on a success. Gore: Melee Weapon Attack: +8: to hit, reach 5 ft., one target Hit: 2d8+4 bludgeoning damage. The target must also succeed on a DC 15 Constitution saving throw. On a failure, the target takes 3d6 fire damage or half as much on a success.
Counterspell (spell) (3rd level/3 slots): Irninür attempts to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, Irninür must make an ability check using her spellcasting ability (Intelligence). The DC equals 10 + the spell's level. On a success the creature's spell fails and has no effect. Irninür can cast counterspell at 4th or 5th level. The interrupted spell has no effect if its level is less than or equal to the level of the spell slot used. Shield (spell) (1st level/4 slots): an invisible barrier of magical force appears and protects Irninür. Until the start of Irninür's next turn, Irninür gets a +5 bonus to her AC including against the triggering attack.
Irninür 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. Irninür regains her spent legendary actions at the start of her turn. Claw Attack: Irninür makes one claw attack. Teleport (Costs two actions): Irninür magically teleports, along with any equipment she carries or wears, up to 120 feet to an unoccupied space she can see. Cast a Spell (Costs three actions): Irninür casts a spell from her list of prepared spells, using a spell slot as normal.
On initative count 20 (losing initiative ties), Irninür takes a lair action to cause on of the following effects; Irninür can't use the same effect two rounds in a row: Magma erupts from a point on the ground Irninür can see within 120 ft. of the Heart Hearth, greating a 20-foot-high, 5 ft. radius geyser. Each creature in the geyser's area must make a DC 15 Dexterity saving throw, taking 6d6 fire damage on a failed save, or half as much on a successful one. A tremor shakes the lair in a 60 ft. radius around the Heart Hearth. Each creatue other than Irninür on the ground must succeed on a DC 15 Dexterity saving throw or be knocked prone. Volcanic gases form a cloud in a 20 ft. raidus sphere centered on a point Irninür can see within 120 ft. of the Heart Hearth. The sphere spreads around corners and its area is lightly obscured. It lasts until initiative count 20 on the next round. Each creature that starts its turn in the cloud must succeed on a DC 13 Constitution saving throw or be poisoned until the end of its next turn. While poisoned in this way, a creature is incapacitated.