Path of Forbidden Magic

Barbarians who follow the Path of the Forbidden Magic have subjected themselves to ancient rituals that no mortal was meant to endure. Through blood sacrifices, forbidden incantations, or communion with entities beyond the Material Plane, they have allowed otherworldly powers to corrupt their bodies. 

When these Barbarians enter their Rage, the magic within them awakens, manifesting through grotesque transformations, supernatural abilities, and unnatural resilience. Rather than casting spells, they channel forbidden magic through their bodies, transforming their fury into a weapon of supernatural destruction. 

Level 3: Dark Knowledge

Your exposure to forbidden rituals has granted you an unnatural understanding of occult practices. 

Whenever you make an Intelligence (Arcana) or Intelligence (Religion) check, you gain a bonus to the roll equal to your Constitution modifier (minimum of +1). 

Level 3: Powers From Beyond

When you enter your Rage, you can call upon the otherworldly magic that has corrupted your body. Choose one of the following transformations. Its benefits last until your Rage ends. 

Otherworldly Vision. Your eyes transform, allowing you to perceive things hidden from mortal sight. You gain Darkvision with a range of 120 feet, and you can see normally through magical Darkness within that range. Additionally, you have a Blindsight with a range of 30 feet. 

Tentacles of the Hidden One. Two grotesque tentacles emerge from your body. These tentacles can't wield weapons or shields, but they can manipulate objects and grapple creatures. 

You can use your tentacles to make Unarmed Strikes. When you use a tentacle to deal damage with an Unarmed Strike, it deals Bludgeoning damage equal to 1d4 plus your Strength modifier instead of its normal damage. 

Whenever you hit a creature with a damaging Unarmed Strike using a tentacle, you can also attempt to grapple that creature as part of the same attack, provided you have a free tentacle. The target makes its saving throw against the grapple as normal. Additionally, you can make one Unarmed Strike with a tentacle as a Bonus Action. 

Vile Excrement. Your body produces a corrosive acid that you can expel at your enemies. When you take the Attack action, you can replace one of your attacks with a ranged attack against a creature within 60 feet of yourself. You use your Constitution modifier for the attack and damage rolls. On a hit, the target takes 1d8 plus your Constitution modifier Acid damage.

The damage increases to 2d8 at Barbarian level 5, 3d8 at level 11, and 4d8 at level 17. 

Fiendish Resistance. Your flesh hardens and twists with infernal corruption. You gain Resistance to Fire, Poison, and Cold damage. Additionally, you have immunity to the poisoned condition.

Fiendish Resistance

Your flesh hardens and twists with infernal corruption. You gain Resistance to Fire, Poison, and Cold damage. Additionally, you have immunity to the poisoned condition.

Otherworldly Vision

Your eyes transform, allowing you to perceive things hidden from mortal sight. You gain Darkvision with a range of 120 feet, and you can see normally through magical Darkness within that range. Additionally, you have a Blindsight with a range of 30 feet. 

Tentacles of the Hidden One.

Two grotesque tentacles emerge from your body. These tentacles can't wield weapons or shields, but they can manipulate objects and grapple creatures. 

You can use your tentacles to make Unarmed Strikes. When you use a tentacle to deal damage with an Unarmed Strike, it deals Bludgeoning damage equal to 1d4 plus your Strength modifier instead of its normal damage. These tentacles have a range of 15 feet. 

Whenever you hit a creature with a damaging Unarmed Strike using a tentacle, you can also attempt to grapple that creature as part of the same attack, provided you have a free tentacle. The target makes its saving throw against the grapple as normal. Additionally, you can make one Unarmed Strike with a tentacle as a Bonus Action. 

Vile Excrement

Your body produces a corrosive acid that you can expel at your enemies. When you take the Attack action, you can replace one of your attacks with a ranged attack against a creature within 60 feet of yourself. You use your Constitution modifier for the attack and damage rolls. On a hit, the target takes 1d8 plus your Constitution modifier Acid damage.

The damage increases to 2d8 at Barbarian level 5, 3d8 at level 11, and 4d8 at level 17. 

Level 6: Occult Magic

Your exposure to forbidden rituals has awakened dark magic within your body, allowing you to unleash supernatural powers without casting spells. 

You have a pool of Forbidden Charges equal to your Proficiency Bonus. You can expend one Forbidden Charge to use one of the following abilities. You regain all expended Forbidden Charges when you finish a Long Rest. These abilities aren't spells and can be used while Raging. If an ability requires a saving throw, the DC equals 8 plus your Proficiency Bonus plus your Constitution modifier. 

Infernal Blaze. As a Magic action, you expend one Forbidden Charge to unleash an eruption of hellfire in a 20-foot Emanation originating from yourself. Each creature of your choice in the area must make a Dexterity saving throw, taking 5d8 Fire damage on a failed save or half as much damage on a successful one. 

Necromancer's Fury. When you hit a creature with a weapon or Unarmed Strike, you can expend one Forbidden Charge and use a Bonus Action immediately after the attack to deal an additional 3d8 Necrotic damage to the target. You regain Hit Points equal to the Necrotic damage dealt.

Putrid Wave. As a Magic action, you expend one Forbidden Charge to release a cloud of poisonous gas in a 15-foot Cube. The Cube originates from a point you choose within 5 feet of yourself. Each creature of your choice in the area must succeed on a Constitution saving throw or have the Poisoned condition for 1 minute. An affected creature repeats the saving throw at the end of each of its turns, ending the condition on itself on a success. 

Frozen Damnation. When a creature within 5 feet of you hits you with a melee attack, you can expend one Forbidden Charge and use your Reaction to unleash supernatural frost in a 15-foot Cone directed toward the attacker. Each creature in the Cone must make a Constitution saving throw, taking 4d8 Cold damage on a failed save or half as much damage on a successful one. On a failed save, a creature also has the Restrained condition until the end of your next turn. 

Level 10: Dark Resurgence

The forbidden magic coursing through your body sustains your supernatural abilities and protects you from those who would harm you. You gain the following benefits. 

Eldritch Rejuvenation. When you roll Initiative and have no Forbidden Charges remaining, you regain one Forbidden Charge. 

Malevolent Ward. When you roll Initiative, forbidden magic envelops your body in a protective ward of malevolent energy. You gain Temporary Hit Points equal to your Barbarian level. 

While you have these Temporary Hit Points, whenever a creature hits you with a melee attack, that creature takes 2d8 Psychic damage. 

These Temporary Hit Points last for 1 minute. 

Level 14: Furious Abjuration

The forbidden magic coursing through your body shields you from hostile supernatural forces. 

While your Rage is active, you have Advantage on saving throws against spells and other magical effects.