Tsuno no Oni (5e Creature)
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Akaiyama no Oni (Kazan no Oni)
Large oni (fiend), any evil or chaotic neutral
Saving Throws Dex+5, Con+8, Str+10
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. Ice damage stops this regeneration.
Multiattack. The Yama no Oni makes two attacks, either with its claws or its Kanabo.
Claw (Oni Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 7) slashing damage.
Kanabo. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) Bludgeoning damage.
Burning Rage (Recharge 5-6). The AkaiYama no Oni (Red Mountain Oni) flies into a rage it catches on fire in immediate area around it. Each creature in that area near the Oni (5 feet-10 feet-20 feet maximum) should roll a DC 17 Dexterity saving throw, taking 6 (1d6+2) fire damage on a failed save, or half as much damage on a successful one. This ring of fire lasts for 1d6+2 turns and the Oni can now add 1d4 fire damage (3d4 maximum fire damage) to every attack it makes. If Burning Rage recharges the Red Oni can use his recharge as a reaction to renew the burning rage as well as gain a new rage counter and the fire damage get's cumulative so a Red Rage Oni can deal 2d6+4 fire damage or maximizes at 3d6+6 fire damage to all enemies or even allies withing 20 feet around the oni as the Oni becomes a literally inflamed raging behemoth. Basically as The Red Mountain Oni gets more and more angry the hotter and greater the fire on his body gets. This effect can be dispelled or a rage counter can be removed from a source of Ice/Cold damage. The Red Mountain Oni also gains advantage in combat but all his enemies gain combat advantage against him as he flies into this reckless rage. Other Akaiyama no Oni do not have thier burning rage stack in a cumulative manner in a shared area but the one with the strongest burning rage wins out in the effected area so if one Akaiyama no Oni is at full 3d6+6 fire damage his aura wins out with two other Akaiyama no Oni in close proximity.
"Powerful muscles with red crimson skin, two small red eyes with one great central purple eyes and on it's head one large horn like a waterbuffalo protruding to the left and a smaller one to the right. The Kansai no Oni smashed his way trough the Ashiari pikemen with ease, his burning rage and massive Iron and oak Kanabo crushing the bones or scorching the flesh of his adversaries like they where but mere gourds or cabbage before a butcher and his cleaver. Skulls were pulverized into gibblets in but an instant... what was left of 20 strong men was reduced to pile of broken bones and scorched flesh." Chronicles of the the White jade Shujenga.
Magical Ogres. Oni are sometimes called ogre mages because of their innate magical ability. Though they are only distantly related to true ogres, they share the ogres' habit of joining forces with other evil creatures.
Akaiyama no Oni aka Red Mountain Oni aka Kazan no Oni or Volcanic Oni are some of the most common kinds of Oni in folklore, they have Crimson skin, a purple red eye, massive muscular frame and fly into burning rage while wielding massive spiked iron-oak club known as a Kananbo. They are said to be the brutal Veteran soldiers of the spirit lands and the Oni hordes. All lesser Oni are generally bullied into submission by these Ogre like Oni. When Akai Yama no Oni fly into a rage they catch on fire and get hotter and hotter as they suffer damage in battle which most foes should be wary during this burning rage...thankfully ice magic and dispel can counter this ability, tragically The Red Mountain Oni can wait for a short time and reuse this ability once again.
Red Mountain Oni can be leading swarms of Bakemono or they can be in a warband with other types of mountain oni. They can also be encountered alone as rogue wandering Oni, these are the ones who have deserted from the Oni armies and live by themselves in mountains, volcanoes or hot springs. Rogue Volcanic Oni are generally somewhat less evil and veer towards more neutral alignments CN, N... they can sometimes be rationalized or bribed.
Red Mountain Oni love drinking, especially strong spirits like sake and other rice wines, but they don't mind beer as well. They also love roasted red meat especially with peppers and spices. Spicey food is one of their top favorites but pickled vegetables are generally disgusting to them and they force each other to eat it in bets. They can eat rice or vegetables but they enjoy their food toasted or roasted over a fire. They can eat raw meat but they generally prefer to bath the raw meat in citrus acids and peppers but they enjoy doing it to intimidate humanoids. Red Mountain Oni have a sadistic streak and love bullying as a form of humor.