Change Shape.*** The oni magically polymorphs into a Medium or Large humanoid, into a Large giant, or back into its true form. Other than its size, its statistics are the same in each form. The only equipment that is transformed is its glaive, which shrinks so that it can be wielded in humanoid form. If the oni dies, it reverts to its true form, and its katana reverts to its normal size.

- 1/day each: *ray of frost*, *whirlwind* (DC 18)

Magic Weapons: The oni’s weapon attacks are magical.

Regeneration: The oni regains 10 hit points at the start of its turn if it has at least 1 hit point.

Change Shape.*** The oni magically polymorphs into a Medium or Large humanoid, into a Large giant, or back into its true form. Other than its size, its statistics are the same in each form. The only equipment that is transformed is its glaive, which shrinks so that it can be wielded in humanoid form. If the oni dies, it reverts to its true form, and its katana reverts to its normal size.

- ***Innate Spellcasting.*** The oni's innate spellcasting ability is Charisma (spell save DC 14). It can innately cast the following spells, requiring no material components:
- At will: *darkness*, *invisibility* (self only), *heat metal*
- 3/day each: *animate objects*, *blade barrier* (DC 16), *wall of iron*
- 1/day each: *ray of frost*, *whirlwind* (DC 18)

Magic Weapons: The oni’s weapon attacks are magical.

Regeneration: The oni regains 10 hit points at the start of its turn if it has at least 1 hit point.

Actions

Multiattack: The oni makes two attacks with its claws or its glaive.

Claw: Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 19 (2d8+10) slashing damage plus 10 (3d6) lightning damage.

Glaive: Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 21 (2d10+10) slashing damage plus 10 (3d6) lightning damage. If the target is a creature other than an undead or a construct, it must succeed on a DC 19 Constitution saving throw or lose 10 (3d6) hit points at the start of each of its turns due to an infernal wound. Each time the oni hits the wounded target with this attack, the damage dealt by the wound increases by 10 (3d6). Any creature can take an action to stanch the wound with a successful DC 12 Wisdom (Medicine) check. The wound also closes if the target receives magical healing.

Multiattack: The oni makes two attacks with its claws or its glaive.

Claw: Melee Weapon Attack: [+14] to hit, reach 10 ft., one target. Hit: 19 ([2d8+10]) slashing damage plus 10 ([3d6]) lightning damage.

Glaive: Melee Weapon Attack: [+14] to hit, reach 15 ft., one target. Hit: 21 ([2d10+10]) slashing damage plus 10 ([3d6]) lightning damage. If the target is a creature other than an undead or a construct, it must succeed on a DC 19 Constitution saving throw or lose 10 ([3d6]) hit points at the start of each of its turns due to an infernal wound. Each time the oni hits the wounded target with this attack, the damage dealt by the wound increases by 10 ([3d6]). Any creature can take an action to stanch the wound with a successful DC 12 Wisdom (Medicine) check. The wound also closes if the target receives magical healing.

Details