Anumaramon (Boss Fight)

We finished the Oriental Campaign today with a final battle with Anumaramon.  My PCs were level 20 and they just full on frontal assaulted the palace while their armies were engaging the Typhoon Guard.  I made it clear, the Typhoon Guard, which is mostly oni, would win if the PCs didn’t deal with Anumaramon and then help dispatch the oni.

The palace in my setting – called the Ghost Tower – was a giant glass tower with the only access via flight.  My PCs flew straight up.  They were intercepted by takobake riflemen – an oni/mind-flayer hybrid with void guns that cause targets to fall at an accelerating rate.  Since the PCs were a 100 feet up if they fell the damage would be 1d6 per 10 feet – cumulatively.  They got past the squad easy enough but triggered all the alarms.  I abstracted the assault on the Palace, depending on their fails would determine how they started the battle:

Three checks, each fail increases the penalty of the final battle:

  1. They know your coming.  You start the battle at 90% of your starting hit points and lose 10% of your ki or 1 randomly determined spell or 1 randomly determined magic item use or 1 randomly determined class ability.
  2. First Fail. You lose 1/4 of your hit points OR half your ki OR 1 random limited-use class ability OR 1 random limited/single use magic item.
  3. Second Fail. You lose 1/4 of your hit points OR half your ki OR 1 random limited-use class ability OR 1 random limited/single use magic item.
  4. Third Fail. You lose 1/4 of your hit points OR half your ki OR 1 random limited-use class ability OR 1 random limited/single use magic item.

Anumaramon was supported by the Raven Prince (just an on the fly modified nagpa), Renshi Meidi (pregnant with Anumaramon’s half-oni child – my PCs killed her knowing full well she was pregnant) and Renshi’s guardian akeru no oni (void elemental).  I set it up in such a way that, Anumaramon was very difficult to beat unless they figured out his weakness.  I wanted to avoid a “bag of hit points” fight. First, he was vulnerable to arcane magic of all types and took full damage from spells of that type. However my party had no arcane casters.  Second, was for an Amatatsu heir to sit on the Jade Throne which would strip him of his defences.  Specifically:

  • Move Anumaramon to phase 2 where he was much more vulnerable to damage than phase 1.
  • Prevent Renshi Meidi from moving to phase 2, or reverting her if she already had.

I thought sitting on the throne and making it part of the battle was a nice reward to whichever player had played every session. Only 3 of my six players had actually played every session from the beginning so only 1 of those was the heir.  Two of them were mind controlled, the other was unconscious.  The unconscious pc was carried to the throne where he rolled a natural 20 on his death saving, popped back up with 1 hp and moved everything to phase 2.  Phase 2 may seem statistically imposing but it would eventually be overcome by 6 level 20 PCs.  2 PCs died but they won in the end.  Here are Anumaramon’s phase 1 and phase 2 stat blocks, the DC for abilities in this battle is 25:



AC always hits, but all damage is reduced to 1.

Hit Points 28


  • All attacks only do 1 damage.
  • Aura of Law provided by the Jade Throne, any creature that can see Anumaramon can not break the rules. In terms of combat this includes:
    • Change. May not use no spirit emblems,
    • Change. May not reroll any rolls.
    • Change. May not benefit from healing (10 feet).
    • Time. Creatures can not take bonus actions or reactions.
    • Fate. Anumaramon never gains or suffers from advantage or disadvantage.
    • Movement. No enemies gain the benefit of magical movement.

However, Anumaramon is vulnerable to chaos, including the most chaotic of forces – arcane magic.


  • Scores critical hits on 19 or 20 and uses both the Devil and Giant critical table from DCC.
  • His attacks never miss.


Roll randomly for what Anumaramon does round to round.  At the end of his turn he always releases a void bomb which moves towards the closest PC and always takes 2 rounds to hit.

  1. Mind blast. 3d4 INT, 100 ft. cone. A creature reduced to 0 INT is completely controlled by Anumaramon and can not recover their INT until he releases them or is killed. When released the character suffers the effect of a feeblemind spell until they successfully save.
  2. Void Kanebo. Melee. 50 force damage.  A creature reduced to 0 by this attack is turned to dust.
  3. Darts of Annihilation. For each target, you loose a dart of magical energy. Provided there is an unobstructed path between you and the target, the dart hits. A target with a hp score of 35 or lower disappears, along with everything it was wearing and carrying that is not a relic. A relic drops to the ground in the space the target occupied. Otherwise, the target takes 50 force damage
  4. Void Bomb. Whenever Anumaramon moves he leaves a force bomb in the space he just left.  This bomb works as the dart of annihilation but slowly homes in on targets (5 feet per round).
  5. Demi. Make a CON saving throw or the target’s hit points are quartered.
  6. Multiattack. Roll twice and take 2 actions.



The Jade Champion, Void Yai and Shapeshifting Master of Darkness.

Huge fiend (Oni), lawful evil

Armor Class 19 (great armor)

Hit Points 1,000

Speed 30 ft., fly 60 ft.

STR        DEX        CON        INT        WIS        CHA

26 (+8)    14 (+2)    24 (+7)    22 (+6)    18 (+4)    24 (+7)

Saving Throws DEX +8, CON +13, WIS +10, CHA +13

Skills Arcana +11, Deception +12, Perception +10

Damage Resistances fire; see the invulnerability trait

Damage Immunities cold

Condition Immunities poisoned

Senses truesight 120 ft., passive Perception 14

Languages Oni, Telepathy 120 ft.

Challenge 20 (25,000 XP)

Commanding Voice. Anamurumon imposes a bane (-1d6) on targets of his enchantment spells and has advantage on all Charisma based ability and skill checks.

Chill Shield. Thin and wispy flames wreathe Anamurumon’s body for as long as he wishes, shedding cold but bright light in a 10-foot radius and dim light for an additional 10 feet. Anamurumon may activate and deactivate the aura as a free action. Whenever a creature within 5 feet of him hits him with a melee attack, the shield erupts with flame. The attacker takes 9 (2d8) cold damage from a cold shield.

Fear Aura. Any creature hostile to Anamurumon that starts its turn within 20 feet of him must make a DC 21 Wisdom saving throw, unless Anamurumon is incapacitated. On a failed save, the creature is frightened until the start of its next turn. If a creature’s saving throw is successful, the creature is immune to the Anamurumon’s Fear Aura for the next 24 hours.

Magic Resistance. Anamurumon has advantage on saving throws against spells and other magical effects.

Magic Weapons. Anamurumon’s weapon attacks are magical.

Regeneration. Anamurumon regains 10 hit points at the start of his turn if he has at least 1 hit point.

Invulnerability. Anamurumon ignores the first 10 points of damage from any single attack – magical or otherwise. Even damage above and beyond this amount is halved. Jade weapons ignore the halving of damage after the initial 10 points are nullified. Honourable weapons nullify invulnerability entirely.

Legendary Resistance (3/Day). If Anamurumon fails a saving throw, he can choose to succeed instead.

Void Form. Anamurumon can assume an incorporeal state as part of his movement, allowing him to go through other creatures and objects as if they were difficult terrain. He takes 5 (1d10) force damage if he ends his turn inside an object. In addition, he becomes resistant to all damage while in this form and his AC becomes 23 for the duration. In this form, he appears as a solid black shadow of his true form. He automatically reverts to his normal form at the start of his next turn.

Void Trap. When a void oni uses any teleportation effect on itself, it can choose to arrive at its destination in void form as part of the teleportation. When it does so, it leaves behind a temporary void sphere in a square of its choice that was part of its space before it teleported. The sphere itself moves at a fly speed of 30 feet toward the closest enemy creature on the oni’s next turn. If no appropriate creature is within 30 feet, the sphere does not move that round. If the sphere enters a square occupied by a creature (or if a creature touches the sphere), that creature must make a DC 21 Dexterity saving throw taking 75 (10d6 +40) force damage or half as much on a success. Once the sphere damages a creature with this effect, the sphere vanishes — it also vanishes on its own after 24 hours in the unlikely event that it never discharges on a creature. The concept of the void is a difficult one for many individuals to grasp, for it encompasses more than just an absence of anything. The concept of “void” as an element also represents the heavens above, the dark places between the stars, the nature of the spiritual world, and even the capacity to create and envision new ideas. The void yai represents all of these possibilities, interpreted in a way that exemplifies the evil of the oni race.

Innate Spellcasting. Anamurumon’s spellcasting ability is Charisma (spell save DC 21). Anamurumon can innately cast the following spells, requiring no material components:


Void Kanabo. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 15 (2d6 + 8) bludgeoning damage plus 21 (6d6) fire damage. One of the following effects also triggers:

      • The target must succeed on a DC 21 Constitution saving throw or become poisoned. While poisoned in this way, the target can’t regain hit points, and it takes 21 (6d6) poison damage at the start of each of its turns. The poisoned target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
      • A creature immune to poison instead makes a DC 21 Strength saving throw or is knocked flying 10 feet or 20 feet on a critical fail and falls prone.
      • The void kanabo also scores a critical hit on a 19 or 20. Targets that are critically hit must make a DC 21 Constitution saving throw or becomes staggered until the end of the creatures next turn. A staggered creature can only move, make a bonus or attack action. Regardless of the creature’s abilities or magic items, it can’t make more than one melee or ranged attack during its turn.

Void Missile. Magic Weapon Attack: +14 to hit, range 180 ft., three targets. Hit: 23 (3d10 + 7) force damage. The target must succeed on a DC 21 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Unlimited Shapechanger. Anamurumon magically polymorphs into a non-construct creature of equal to or less than his CR, or back into his true form. Other than his size, his statistics are the same in each form however he gains access to any special movement type the creature has as well as any of its traits and attacks in addition to his normal litany of actions and traits. His equipment also transforms and will function normally if the new shape allows it. Otherwise it is absorbed into the new form. If he dies, he reverts to his true form, and his kanabo reverts to its normal size. He may use this action as bonus action, reaction or spend legendary actions to trigger the effect.


Kanabo. Anamurumon makes a kanabo attack as a reaction to being hit.