Yoru no Oni (Night Ogre) (5e Creature)
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Yoruyama no Oni
Large fiend, any evil alignment
Saving Throws Dex +5, Con +11, Wis +5, Cha +7
Innate Spellcasting. The oni's innate spellcasting ability is Charisma (spell save DC 16). The oni can innately cast the following spells, requiring no material components:
Magic Weapons. The oni's weapon attacks are magical.
Multiattack. The oni makes two melee weapon attacks.
Ono. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) piercing damage.
Freezing Revenge (Recharge 5-6). The oni becomes freezing cold with vengeance in a 20-foot radius area around it. Each creature in that area must make a DC 18 Constitution saving throw, taking 7 (3d4) cold damage on a failed save, or half as much damage on a successful one. For 1 minute after using Freeing Revenge, the oni deals an additional 5 (2d4) cold damage whenever it hits with a weapon attack.
Where the kazan no oni aka the akaiyama no oni is a famous raging berserker that burns hot and hits his foe with his massive club the yoruyama no oni is a more logical, magical foe who uses the freezing nights of the mountains to fuel his powers and defense form of combat. This dark blue or indigo oni will use a door with spikes as a shield while weilding a large ono battle axe from a dead ronin or yamabushi as his main weapon. This oni can summon a freezing ring of vengeance around him to slow his enemies and he can daze them with powerful shield strikes. These "blue" mountain oni act more like loyal guardians to higher level akuma and rakshasas. They pillage the battlefield to cover themselves in the best armor from dead samurai or tiger knights and then expertly sew those scale mail and lamelar armour over their powerful yet portly frames. To add insult to injury these guardians are incredibly tough and they even uses mirror images to confuse their foes into striking the wrong projection of themselves.