Legendary Resistance (3/Day):

• If Kageshin fails a saving throw, it can choose to succeed instead. This ability represents the adaptation power of Mahoraga.

Innate Regeneration:

• Kageshin can regenerate 50 hit points at the start of its turn if it has at least 1 hit point. It cannot regenerate if it has taken radiant damage or if it is incapacitated.

Multi-Headed Fury:

• Kageshin has 5 heads representing the fusion of Nue, Divine Dogs, Great Serpent, Morning Tiger, and Mahoraga. It can use each head to attack in combat. When Kageshin makes a melee attack, it can choose which head to attack with, each providing a unique type of attack.Shifting Form:

• As a shape-shifting Shikigami, Kageshin can assume a serpentine, bird-like, or quadruped form on its turn, altering its movement and attacks. This allows it to use different action options and adapt to combat, changing its size (Large or Huge) or flight capabilities.

Thunderstorm Aura:

• The area within 120 feet of Kageshin is filled with crackling lightning. Any creature that starts its turn within this radius takes 10 (3d6) lightning damage. This ability reflects Nue’s lightning powers.

Multiattack:

• Kageshin makes three attacks: one with its bite, one with its claws, and one with its tail, or it can use its Breath of the Shadow God.

Bite (Thunderous Strike):

• Melee Weapon Attack: +15 to hit, reach 10 ft., one target.
• Hit: 30 (4d10 + 8) piercing damage plus 18 (4d8) lightning damage.

Claws (Serpent Constriction):

• Melee Weapon Attack: +15 to hit, reach 15 ft., one target.
• Hit: 28 (4d8 + 8) slashing damage. The target must succeed on a DC 23 Strength saving throw or be restrained by the fusion’s claws. The restrained target takes 15 (3d6) bludgeoning damage at the start of Kageshin’s next turn.

Tail (Mahoraga’s Might):

• Melee Weapon Attack: +14 to hit, reach 20 ft., one target.
• Hit: 40 (5d10 + 8) bludgeoning damage, and the target is knocked prone.

Breath of the Shadow God (Recharge 5-6):

• Kageshin exhales a devastating burst of energy in a 60-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 70 (20d6) lightning and necrotic damage on a failed save, or half as much damage on a successful one. This attack represents the combination of Nue's lightning and Mahoraga's evolving curse.

Tenfold Strike:

• Melee Weapon Attack: Kageshin makes 5 melee attacks, each with its bite, claws, or tail, in a single turn. Each attack uses a different head (Nue’s lightning bite, Great Serpent’s constricting tail, etc.). If Kageshin uses this action, it cannot use its Breath of the Shadow God for 1d4 turns.

Domain Expansion: Tenfold Shadow Realm

Domain Expansion: Tenfold Shadow Realm Features:

Area of Effect:

• The Tenfold Shadow Realm expands in a 100-foot radius around Kageshin, shaping the environment into a swirling blend of stormy clouds, crackling lightning, and overgrown jungle. The terrain becomes shifting and unstable, with parts of the ground constantly regenerating and reforming as though influenced by Round Deer’s healing abilities and Nue's stormy power.

Enhanced Abilities:

While within the Tenfold Shadow Realm, Kageshin gains the following benefits:

1. Lightning Storm: The storm within the domain is constantly alive with electrical discharges. Creatures within the domain must succeed on a DC 22 Constitution saving throw at the start of their turn or take 20 (6d6) lightning damage.
2. Cursed Adaptation: Kageshin’s attacks become more devastating while inside the domain. All of Kageshin's melee attacks (bite, claws, and tail) gain +2 bonus to attack rolls and deal an additional 10 (3d6) lightning damage, as the domain draws power from Nue's lightning.
3. Regenerative Aura: Kageshin's regenerative abilities are amplified within its domain. It regenerates 50 hit points at the start of its turn, even if it’s below half its maximum hit points. This regeneration cannot be stopped by any effect that prevents healing.
4. Shadow Manipulation: Kageshin can manipulate shadows within the domain to attack or defend. It can use its bonus action to either:
   • Shadow Tendrils: Kageshin summons shadowy tendrils to grab and restrain creatures. Any creature within 30 feet of Kageshin must succeed on a DC 22 Strength saving throw or be restrained for 1 minute. A restrained creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.
   • Cursed Barrier: Kageshin can form a defensive shield of pure cursed energy for itself or an ally within its domain. This barrier absorbs 40 hit points worth of damage before dissipating.

Environmental Effects:

• The Tenfold Shadow Realm also distorts the environment, giving Kageshin tactical advantages:
  • Illusory Terrain: The terrain can shift unpredictably. Any creature within the domain that attempts to cast a spell requiring sight must succeed on a DC 18 Intelligence saving throw or have the spell fail as the environment distorts and obscures vision.
  • Lurking Shadows: Kageshin can cause the shadows to disappear and reappear within the domain. Once per turn, it can teleport up to 60 feet to an unoccupied space it can see within the domain. After teleporting, it has advantage on its next attack roll.
  • Regeneration Zones: At the end of each of Kageshin’s turns, a 10-foot radius area of the domain becomes a Regeneration Zone, healing 20 hit points per turn for any creature inside it (including enemies). Kageshin can use this to strategically heal or trap enemies within the healing zone.

Duration and Limitations:

• The Tenfold Shadow Realm lasts for 1 minute and cannot be dispelled by normal means. Once activated, it cannot be used again until after a long rest or a short rest with a DC 25 Constitution saving throw to recharge it.
• Kageshin can be disrupted in its domain if it is hit by force damage or radiant damage while the domain is active. If Kageshin is incapacitated or knocked unconscious, the domain immediately collapses.

Legendary Actions - Domain Expansion Usage:

When Kageshin activates Tenfold Shadow Realm, it gains the following Legendary Actions during the duration of the domain.

1. Crushing Lightning (Costs 1 Action):

   • Kageshin summons a bolt of lightning to strike a creature within the domain. The creature must make a DC 22 Dexterity saving throw or take 40 (12d6) lightning damage and be stunned until the end of its next turn. A successful save reduces the damage by half and negates the stunned condition.

2. Shadow Barrage (Costs 2 Actions):

   • Kageshin summons shadowy projectiles from the darkness around it and fires them at up to three targets within the domain. Each target must make a DC 22 Dexterity saving throw, taking 30 (8d6) piercing damage on a failed save, or half as much on a successful one.

3. Regeneration Burst (Costs 3 Actions):

   • Kageshin can trigger a healing surge within its domain, regaining 60 hit points and allowing all allies (or itself) within the domain to regain 10 (3d6) hit points. All creatures within the domain must make a DC 20 Constitution saving throw, taking 25 (7d6) necrotic damage on a failed save or half on a successful one.

Adaptation (Recharge 2-3):

• Trigger: When Kageshin is hit by an attack or affected by a harmful condition, it can use its Adaptation reaction to change its form and resist the effect in a specific way.

Kageshin can choose one of the following adaptations as a reaction when it is hit by an attack or subjected to a harmful condition (such as being blinded, paralyzed, poisoned, or frightened). Kageshin gains resistance to the damage from the triggering attack or advantage on the saving throw against the condition.

Kageshin can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Kageshin regains spent legendary actions at the start of its turn.

Shadow Dash:

• Kageshin moves up to half its speed without provoking opportunity attacks. It can take this action twice in a turn, making it exceptionally mobile.

Crackling Roar (Costs 2 Actions):

• Kageshin releases a terrifying roar filled with electrical energy. Each creature within 60 feet of it must succeed on a DC 22 Wisdom saving throw or be frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Regeneration Burst (Costs 3 Actions):

• Kageshin instantly regenerates 40 hit points. Additionally, all creatures within 60 feet must make a DC 20 Constitution saving throw, taking 25 (6d6) necrotic damage on a failed save or half as much on a successful one.

When Kageshin's hit points drop below half, it gains access to the following Mythic Actions, which can be used once per turn, at the end of the Mythic Action phase. These actions represent the ultimate power of its domain and fusion of Shikigami.

Shadow Storm Ascension 

• Kageshin unleashes its full storm-like power.
• Effect: Kageshin's body surges with uncontrollable energy, and it conjures a massive storm that blankets the battlefield in a terrifying swirl of lightning, darkness, and cursed energy. This storm creates a 500-foot radius area of effect that persists until the end of its next turn.
  • All creatures within the storm’s area must make a DC 22 Constitution saving throw or take 60 (18d6) lightning and necrotic damage, or half as much on a successful save.
  • Kageshin is immune to the damage it deals and can choose to regain 20 hit points for every creature within the storm’s area that fails its saving throw.

Shadowstep of the Beast

• Kageshin takes the form of a terrifying hybrid creature and strikes with ferocity.
• Effect: Kageshin immediately teleports up to 60 feet to a space it can see within its domain, and as it does so, it transforms momentarily into a hulking beast made entirely of shadows and cursed energy. This transformation allows it to attack all creatures within 10 feet of its destination with a powerful shadow-infused bite or claw strike.
  • This strike deals 40 (8d6) slashing damage plus 20 (6d6) necrotic damage.
  • All creatures hit by the attack must make a DC 20 Constitution saving throw or be frightened for 1 minute. They can repeat the saving throw at the end of each of their turns, ending the effect on a success.

Eclipsing Grasp of Mahoraga

• Kageshin summons the dark, infinite power of Mahoraga's cursed form.
• Effect: Kageshin summons the infinite power of Mahoraga, creating an area of supernatural gravity centered on itself. The gravitational pull distorts space, causing all creatures within a 30-foot radius to be pulled toward Kageshin.
  • Each creature must make a DC 22 Strength saving throw or be pulled to Kageshin’s space, becoming grappled and restrained until the end of their next turn.
  • While grappled, the creatures take 30 (8d6) necrotic damage at the start of each of Kageshin’s turns.
  • Kageshin can choose to slams any creature within the grasp into the ground, dealing 50 (10d10) bludgeoning damage to all restrained creatures.
  • After the grasp ends, all affected creatures must make a DC 20 Wisdom saving throw or suffer blinded and deafened for 1 minute as their senses are overwhelmed by cursed energy.

Cursed Rebirth

• Kageshin taps into its regenerative essence, coming back stronger than ever.
• Effect: Kageshin’s regenerative powers take over when it's critically injured, instantly mending its form. Kageshin can use Cursed Rebirth as a free action when its hit points drop below half.
  • Regeneration: Kageshin regains 100 hit points and immediately removes any conditions (except stunned) affecting it, such as frightened, paralyzed, or poisoned.
  • In addition to healing, Kageshin's next attack or ability gets a +2 bonus to attack rolls and deals an additional 20 (6d6) necrotic damage.

Final Hour of the Ten Shadows

• Kageshin sacrifices the last of its Shikigami powers to deliver a cataclysmic blow.
• Effect: In its final moments, when Kageshin is on the brink of death, it can perform the Final Hour of the Ten Shadows. This devastating action combines all the powers of its Shikigami into one terrifying attack.
  • Effect: Kageshin channels all of its energy into a massive beam of cursed light, sweeping through a 100-foot line and dealing 100 (30d6) force and lightning damage to all creatures in its path. Creatures caught in the beam must make a DC 24 Dexterity saving throw or take full damage, or half as much on a successful save.
  • Aftermath: Once Kageshin uses this ability, it immediately dies or is reduced to 0 hit points. The aftermath leaves a searing trail of cursed energy that remains in the area, causing all creatures that enter the line for the next minute to suffer 10 (3d6) necrotic damage at the start of their turns.

    Description

Kageshin, the Tenfold Shadow Dragon, is a terrifying fusion of ancient cursed energy and the mighty beasts of the Ten Shadows Technique. Standing over 50 feet tall, its form is a massive, coiling serpent-like creature with multiple heads representing its Shikigami: an electric bird, a venomous serpent, a shadowy wolf, a predatory tiger, and the monstrous Mahoraga. Its body is wrapped in ethereal, shadowy wings that crackle with lightning, and its eyes gleam with an unsettling mix of cursed power.

Kageshin embodies chaos, constantly shifting between physical and ethereal forms, making it an unpredictable force of destruction. Its presence warps the environment, unleashing storms of lightning, cursed energy, and gravitational forces. Tied to its summoner through a dark, life-draining bond, Kageshin is both a weapon of unimaginable power and a terrifying curse, as it feeds on its user’s life force and sanity with every summon.