The Path of the Fundamental Chaos is the barbarian subclass of Ashton Greymoore. It is implied to be connected to dunamancy, as Ashton's head injury was healed with, among other things, a Potion of Possibility.

Chaos Burst

Upon choosing this path at level 3, a Fundamental Chaos barbarian can choose to deal extra damage on an attack with a chaos burst. This allows them to add additional damage dice to an attack with a melee weapon a number of times per day equal to their proficiency bonus. Damage type depends on a 1d8 roll and includes acid, lightning, force, cold, fire, psychic, thunder, and poison. The barbarian regains chaos Burst on a short or long rest.

At 3rd level the damage die is 2d4. The damage die increases at higher levels, becoming 2d6 at 14th level.

Fundamental Force enhancement I

At 6th level, a raging barbarian can choose to spend a use of Chaos Burst, triggering a different effect for each type of rage.

* Hyper Rage (Time): The barbarian's speed is doubled, they don't provoke opportunity attacks and they can use a bonus action to make an additional attack.

* Wormhole Strike (Space): The barbarian can open two portals, one next to themselves and another at a point within 60 feet. They may attack a creature through this portal as if the two portals are adjacent to one another. This attack deals an additional 1d6 damage.

* Density Well (Gravity): The barbarian cannot be moved against their will or knocked prone, and when they hit a creature with a melee weapon attack it deals additional damage and must make a Strength saving throw or be knocked prone.

* Dreadful Misfortune (Potential): When a creature misses the barbarian with an attack, the barbarian can use their reaction to force the creature to re-roll the attack against itself, on a hit the creature takes half damage.

Erratic Defense

At 10th level, when hit by an attack the barbarian can use their reaction to become resistant to all damage, and an additional random effect occurs depending on a 1d4 roll of a rage type. Once this ability is used, it can't be used again until the barbarian finishes a short rest.

* Time: The attacking creature's speed is halved and they can't take reactions, until the end of its next turn.
* Space: The attacking creature is teleported 30 feet to a space of the barbarian's choice.
* Gravity: The attacking creature is pushed 30 feet away from the barbarian.

 

Fundamental Force enhancement II

At 14th level, a raging barbarian can choose to spend a use of Chaos Burst, triggering a different effect for each type of rage:

* Acceleration Wave (Time): The barbarian chooses up to ten creatures they can see, and grants a burst of speed.
* Scattering Blow (Space): When the barbarian hits a creature with an attack, the barbarian and the target can teleport to a space within 30 feet.
* Singularity Assault (Gravity): The target takes 2 damage dice worth of additional force damage. Creatures within 30 feet of the target must make a Strength save or be pulled to the closest empty space adjacent to the target.
* Mark of the Messy End (Potential): Whenever the barbarian misses their attack they can magically mark a target. Attack rolls against the target score a critical hit on an 18 through 20 until the start of the barbarian's next turn.