Large fiend, chaotic evil
- Armor Class
- 16 (natural armor)
- Hit Points
- 243 (18d10 + 144)
- Speed
- 40 ft.
- Challenge
- 25 (75,000 XP)
- Saving Throws
- Con +16, Dex +9, Wis +14
- Skills
- Survival +14, Perception +14, Intimidation +12
- Damage Resistances
- fire; lightning
- Damage Immunities
- cold; poison; bludgeoning, piercing, slashing from nonmagical attacks
- Condition Immunities
- charmed; frightened; poisoned
- Senses
- truesight 120 ft., passive Perception 24
- Languages
- Abyssal, Giant, telepathy 120 ft.
Traits
If Kostchtchie fails a saving throw, he can choose to succeed instead.
Kostchtchie has advantage on saving throws against spells and other magical effects.
Actions
Kostchtchie makes two melee attacks, only one of which can be a bite attack.
Melee Weapon Attack: +18 to hit, reach 5 ft., one creature. Hit: 13 (1d6 + 10) piercing damage.
Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage, or 21 (2d10 + 10) bludgeoning damage when used with two hands, and the weapon emits a burst of cold that deals 10 (3d6) cold damage to each creature within 30 feet of it.
Legendary Actions
Kostchtchie makes one melee weapon attack.
Kostchtchie moves up to his speed.
Kostchtchie curses one creature he can see within 60 feet of him. The cursed creature gains vulnerability to all damage dealt by Kostchtchie until the end of Kostchtchie's next turn.
Spellcasting
Kostchtchie's innate spellcasting ability is Charisma (spell save DC 20). He can innately cast the following spells, requiring no material components: