No Oni, Shikibu (CR 10)

Small Outsider (Evil and Shadowlands)
Alignment: Always chaotic evil
Initiative: +7 (+3 Dex, +4 Improved Initiative); Senses: Listen +9 and Spot +9
Languages: Telepathy 100 ft.

AC: 21 (+1 size, +3 Dex, +7 natural), touch 14, flat-footed 18
Hit Dice: 5d8+5 (27 hp); DR: 10/jade
Fort +5, Ref +7, Will +5
Speed: 20 ft.
Space: 5 ft./5 ft.
Base Attack +5; Grapple -4
Attack: 2 slams +8 melee
Full Attack: 2 slams +8 melee
Damage: Slam 1d4+2
Special Attacks/Actions: Spell-like abilities, fear aura
Abilities: Str 14, Dex 16, Con 12, Int 15, Wis 13, Cha 15 (Ego: 9)
Special Qualities: SR 20, oni qualities, regeneration 5, ethereal escape
Feats: Dodge; Improved Initiative
Skills: Bluff +10, Diplomacy +6, Disguise +10, Hide +11, Intimidate +12, Knowledge (Shadowlands) +10, Listen +9, Move Silently +11, Search +10, Sense Motive +9, and Spot +9
Advancement: 6-15 HD (Small)
Climate/Terrain: Shadowlands
Organization: Solitary
Treasure/Possessions: Standard

Source: Oriental Adventures

Spell-Like Abilities: At will - animate dead, bestow curse, chill touch, cloud of Taint, darkness, death knell, desecrate, detect thoughts, enlarge, ethereal jaunt, scare. These abilities are as the spells cast by a 7th-level mahosukai (save DC 19 + spell level).

Fear Aura (Su): Oni are shrouded in a constant aura of terror and evil. Creatures within a 30-foot radius must succeed at a Will save (DC 14) or become shaken. Shaken creatures suffer a -2 morale penalty on attack rolls, (weapon damage rolls, and saving throws.

Regeneration (Ex): Oni take normal damage from jade or Kuni crystal weapons, and from honorable or blessed weapons of at least +2 enhancement.

Ethereal Escape (Su): If reduced to 0 hit points or lower, a shikibu no oni's spirit immediately leaves its body in ethereal form (as ethereal jaunt). The spirit can then inhabit a nearby corpse, animating it and slowly transforming it into a replica of the oni's original form. The transformation takes 2d4 minutes, but the oni is fully capable of continuing battle in its new body, with all its hit points fully restored. The oni can only remain in spirit form for 1 minute. It can move ethereally during that rime, but cannot pass through jade. If the oni cannot enter a corpse during that time, it is destroyed.

Immunities (Ex): Oni are immune to poison.

Resistances (Ex): Oni have cold, fire, and acid resistance 10.

Alternate Form (Su): Oni can assume any humanoid form of Small to Large size as a standard action. This ability is similar to the polymorph self spell but allows only humanoid forms. When using this ability, oni gain a +10 circumstance bonus on Disguise checks.

Telepathy (Su): Oni can communicate telepathically with any creature within 100 feet that has a language.

Skills: All oni receive a +10 circumstance bonus on Disguise checks when using their alternate form ability.

Evil Subtype

A subtype usually applied only to outsiders native to the evil-aligned Outer Planes. Evil outsiders are also called fiends. Most creatures that have this subtype also have evil alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has an evil alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the evil subtype overcomes damage reduction as if its natural weapons and any weapons it wields were evil-aligned (see Damage Reduction).

Shadowlands Subtype

Shadowlands are the source of evil in the campaign setting of Rokugan, the festering pit from which oni crawl, slither, and fly to wreck their foul destruction on humanity. The denizens of the Shadowlands are inhuman monstrosities. Many of them are spirits bound into corporeal form, and most are shapeshifters. Of all the creatures found in the Shadowlands, only the nezumi remain uncorrupted by the foul taint of the place - all others are utterly, irredeemably evil.

Shadowlands creatures share a certain immunities and vulnerabilities. They are immune to harmful effects of the Shadowlands Taint, for they are already fully corrupted by their very nature. Even if they have damage reduction, they are harmed by jade and obsidian weapons, and they cannot regenerate or naturally heal wounds dealt by such weapons. They are also affected by crystal weapons (Chapter 8, Oriental Adventures) (Note: Non-magical weapons made out of crystal, or crystal weapons created by means other than the Craft Crystal Weapon feat, have no special properties against Shadowlands creatures.)

For purposes of detect Taint, spellcasting, and other effects, a Shadowlands creature is considered to have a Taint score equal to half its Charisma score (round down). Undead creatures add +1 to this number, while outsiders add +2.