uncommon ne large cold undead 

Perception +33; darkvision

Languages Common (Can't Speak Any Language)

Skills Athletics +39

Str +9 Dex +2 Con +10 Int -5 Wis +0 Cha -2

Items +3 greater striking greatsword

AC  45; Fort +39, Ref +27, Will +33

HP 475, negative healing; Immunities cold, death effects, disease; Weaknesses fire 20

Freezing Death (aura, cold, evocation, primal) 20 feet. A creature that starts its turn in the aura takes 6d6 cold damage (DC 42 basic Fortitude). If the creature is grabbed or restrained by the sthira, it takes one degree of success worse than it rolled.

Attack of Opportunity [R]

Frozen to the Touch (cold) A creature that damages the sthira with an unarmed attack, tries to Grapple it, or otherwise touches it takes 6d6 cold damage (DC 42 basic Fortitude).

Speed 25 feet

Melee [>] greatsword +38 (magical, versatile p, reach 10 feet), Damage 3d12+15 slashing plus 2d6 cold and frostbite

Melee [>] fist +38 (magical, reach 10 feet), Damage 3d8+15 bludgeoning plus 2d6 cold, frostbite, and Improved Grab

Primal Innate Spells DC 39, attack +31; 10th massacre; 9th polar ray (×2), storm of vengeance (hail only each round), wall of ice; Cantrips (10th) ray of frost

Frostbite A creature that takes cold damage from a sthira's Strikes or aura must attempt a DC 42 Fortitude save. A creature that already has persistent cold damage from frostbite ignores this effect. Critical Success The creature is unaffected, and is temporarily immune to this ability for 1 hour.Success The creature is unaffected.Failure The creature takes 3d6 persistent cold damage.Critical Failure As failure, but the creature is also drained 1.

Create Sthira (primal, necromancy) When a creature dies while it has persistent cold damage from the sthira's frostbite, the creature rises as a sthira in 24 hours. If the creature is grappled by the sthira when it dies, the dying creature becomes permanently fused with the sthira instead. In this case, the sthira immediately recovers a number of Hit Points equal to the half the dead creature's maximum Hit Points.

Fists of the Ruby Phoenix #3: King of the Mountain, page 87.