Demonbound Warrior

The Demonbound Warrior is a terrifying figure, a warrior who binds the souls of fiends and aberrations into their equipment. Their armor and weapons become sentient extensions of their will, whispering temptations and granting otherworldly power. The very essence of the bound creatures manifests in their equipment, transforming them into a living embodiment of infernal might.

Soul Infusion

Soul Binding: You gain the ability to bind the souls of fiends or aberrations into your
equipment. The number of items you can bind equals your proficiency bonus.

To bind a soul:
Unwilling Souls: The creature must be killed or subdued, and you must perform a
1-hour ritual. This ritual requires an Arcana check (DC 10 + the creature’s CR).
On a failure, psychic backlash deals damage equal to twice the creature’s CR.

Willing Souls: If the creature willingly offers its soul, the ritual takes only 10
minutes, and no Arcana check is required.

Sentient Equipment: Bound items gain sentience and take on a physical motif reflective
of the bound soul:

• A beholder’s soul might cause the item to sprout additional eyes or twitching
  tentacles.
• A demon’s soul might adorn the armor or weapon with jagged spikes, scales, or
  glowing infernal runes.
• An aberration’s soul might warp the item, creating shifting patterns, pulsating
  growths, or eerie colors.

These changes are permanent unless the soul is exorcised or replaced.

Stat Enhancements: Bound equipment grants a +2 bonus to a specific ability score
based on its type:

• Legs/Boots: Dexterity.
• Arms/Bracers/Gloves: Strength.
• Chest/Armor: Constitution.
• Helm/Mask: Intelligence.
• Jewelry/Amulets/Rings: Charisma.
•  No Stat Cap: These bonuses can raise your ability scores above 20

Corruption Risk:
If you attempt to bind more items than your proficiency bonus allows, you must
make a Wisdom saving throw (DC 10 + the total CR of all bound creatures) each
day. On a failure, the souls take control of your body, turning you into a
monstrous living armory until freed by greater restoration or similar magic.

Arms/Bracers/Gloves Bind

While bound to this armor/gear type, you will gain a bonus to the corresponding stat.

Chest/Armor Bind

While bound to this armor/gear type, you will gain a bonus to the corresponding stat.

Helm/Mark Bind

While bound to this armor/gear type, you will gain a bonus to the corresponding stat.

Jewelry/Amulets/Rings Bind

While bound to this armor/gear type, you will gain a bonus to the corresponding stat.

Leg/Boots Bind

While bound to this armor/gear type, you will gain a bonus to the corresponding stat.

Abyssal Resilience and Weapon Infusion

Infused Weaponry: You can bind a soul into a weapon, granting it additional power:

• The weapon deals an additional 1d8 damage of the creature’s damage type (e.g.,
  fire for a demon, psychic for an aberration).
• Weapons infused with souls from CR 10+ creatures deal an additional 2d8
  damage.

 Willing Weaponry: If the soul is willing, the weapon gains additional benefits:

• You can telepathically communicate with the weapon.
•  Once per long rest, you can reroll a natural 1 on an attack roll with the
  weapon.

Resilience of the Abyss: Infused armor grants you resistance to a damage type
associated with the bound soul (e.g., fire, necrotic, psychic). The resistance type is
determined by the creature’s traits.

Aesthetic Transformation: Infused weapons and armor transform to reflect the essence
of the bound creature:

• A fiery demon weapon might emit smoke or glow with ember-like veins.
• A tentacled aberration weapon might writhe unnaturally when unsheathed.

Armor infused with a shadowy fiend might emit faint whispers or a flickering
dark aura.

Souls’ Boons

The abilities granted by bound equipment grow stronger:

• Legs/Boots: Gain a +10 bonus to your movement speed and the ability to Dash or
  Disengage as a bonus action.
• Arms/Bracers/Gloves: When you land a critical hit, the target is restrained until the end
  of your next turn as dark tendrils bind them.
• Chest/Armor: Gain temporary hit points equal to your Fighter level at the start of
  combat.
•  Helm/Mask: Gain the ability to cast detect magic and comprehend languages at will.
• Jewelry: Gain advantage on Charisma (Persuasion) and (Intimidation) checks, and your
  Charisma score increases by an additional +2.
• Willing Souls Clause: If one or more of your bound souls are willing: The first Wisdom saving throw to resist corruption each day is automatically
  successful.
• Once per long rest, a willing soul can intervene, allowing you to reroll a failed saving throw or attack roll.

Bound Souls’ Dominion

• Greater Infusions: Weapons and armor gain advanced properties:
•  Infused weapons deal an additional 3d8 damage of the creature’s type.
• Infused armor grants immunity to one damage type tied to the soul (e.g.,
  immunity to fire for a fire demon).
• Soulflare Aura: As an action, you can unleash the combined power of your bound souls
  for 1 minute: 
  Enemies within 15 feet of you take damage equal to your Fighter level at the start
  of their turns.
  You have resistance to all damage
• Willing Souls Clause: If more than half of your bound souls are willing, your
  Soulflare Aura deals an additional 1d8 damage, and willing souls can
  communicate warnings or guidance to you and your allies.
•  At the end of the duration, you must make a Wisdom saving throw (DC 15). On a
  failure, you take 4d12 psychic damage as the unwilling souls lash out.

Living Armory

Maximum Infusion: You can bind a number of souls equal to double your proficiency
bonus. However, corruption risks increase significantly:

1. If you bind more souls than your proficiency bonus, you must make Wisdom
   saving throws (DC 15 + the CR of the highest bound creature) at the start of each
   day.
2. On a failed save, you lose control, becoming a terrifying amalgam of armor and
   weapons. You retain control only until the end of combat, at which point the souls
   attempt to escape or destroy your body.

Unleashed Form: You may fully embrace the power of the souls as a bonus action. For 1
minute:

1.  You gain a flying speed of 60 feet.
2.  You can attack twice per attack action, adding an additional 3d8 to each attack.
3. You are immune to charm, fear, and paralysis.
4. Willing Souls Clause: Each willing soul reduces the psychic backlash at the end
   of this form by 1d12 (to a minimum of 0). (Willing souls also reduce the
   corruption save DC by 5.)