For some barbarians, the power of their rage develops beyond the limits of what their body can contain. The Path of the Riastrad is a specialized progression tree for barbarians that substitutes the typical barbarian rage skill for a high risk, high reward Warp Spasm skill that twists the barbarian's form into impossible, terrible shapes; physical manifestations of the barbarian's endless battlelust.

Warp Spasm

Starting when you choose this path at 3rd level, your rage still confers bonus rage damage and gives advantage on strength checks and saving throws as normal, but no longer confers resistance to bludgeoning, slashing and piercing damage against nonmagical weapons. Your rage instead now confers 2 Warp Spasm effects to your character, rolled on a d20 from the Warp Spasm Effect Table below as well as 1 side effect, rolled on a d12 from the Side Effects table below. If the rolls for the 2 Warp Spasm effects are identical, reroll the 2nd effect until you get a different result.

Warp Spasm Effects

d20	Effect
1	Every muscle in your body stretches and shifts, growing outwards. Your size becomes Large, you gain +2 Strength, and your attacks do an additional 1d4 force damage.
2	Fiery flakes as large as a ram's fleece spew out of your throat. Gain fire breath weapon as an action 3 times per rage- 15 ft cone, DC 13 Dexterity saving throw or take 3d6+rage bonus fire damage, no damage on a save.
3	One arm becomes long, sinewy and tightly muscled. Gain +2 Strength and an extra 5 feet of reach.
4	Your hair bristles into razor sharp spikes. A creature that touches the barbarian or hits it with a melee attack while within 5 feet of it takes 1d10 piercing damage.
5	Your kneecaps shift backwards inside your legs; making them digitigrade. +2 Dexterity, speed increases by 15.
6	Your back muscles knot and twist themselves into the shape of a demon's face. +2 to attack rolls, and rage bonus damage is doubled.
7	Your triceps muscles triple in size. Thrown weapon normal and long range value is tripled.
8	You grow large, clawlike hands and feet with 7 digits per limb. Speed increased by 5, unarmed attacks do 1d4 extra slashing damage and you gain a climb speed equal to double your walking speed.
9	The skin on your face peels back, exposing your skull and muscle tissue. At the start of your rage, any living creature you are facing that can see you within 60 feet must make a DC 13 Wisdom saving throw or be frightened for 1 minute. Creatures can make the save again at the end of their turns, but the save DC increases to 14 if you have damaged them since your last turn.
10	Your back muscles and spinal cord twist and turn in fury, increasing your swing speed. Gain 1 additional attack roll per turn.
11	Your head begins glowing with brilliant, magical light in a 30 foot radius and dim light for an additional 30 feet. Any ally moving into a space within 30 feet of you or starting their turn there can gain temporary HP equal to your barbarian level once per rage. You can also use a bonus action to force 1 enemy per rage to make a DC 14 Constitution save or be blinded for 1 round.
12	One leg becomes impossibly dense and muscled. + 2 Dexterity, jump height is tripled.
13	Your trapezius and shoulder muscles warp and expand to form a dense muscular covering over your upper body. You are immune to critical hits, and your strikes are considered critical on a 19 or a 20.
14	The veins under your skin begin to blacken and pulse erratically. As a reaction when you take piercing or slashing damage, you can force black blood to spray from your wound, causing each creature within 5 feet of you to take 2d6 poison damage.
15	Your skeleton thickens and forms protective razor sharp bone-spur structures. +2 AC, and any creatures that grapple or are grappled by you take 1d6 slashing damage at the start of their turns.
16	Your flesh begins to roil, with new skin quickly covering wounds. Gain regeneration 4 once per round. This effect does not apply to temporary hitpoints.
17	Your heart triples in size, and becomes visible on the outside of your chest. Gain the effects of the Haste spell for the duration of the rage.
18	Your muscles rearrange themselves in a more resilient pattern. Gain resistance to all nonmagical damage. This effect does not apply to temporary hitpoints.
19	Your brainstem expands along your spine, covering your back muscles with brainlike matter. Gain immunity to psychic damage and resistance to magical elemental damage.
20	You may roll twice and select either result as your warp spasm effect.

 

Side Effects

d12	Effect
1	You lose the ability to discern friend from foe. At the start of every turn during your rage, make a DC 10 Wisdom saving throw. A failed save compels you to move up to your speed towards the nearest living creature you can see and make at least 1 melee attack.
2	Your feet and shins switch to the rear and your heels and calves switch to the front. Speed reduced by 15.
3	One of your eyes gets sucked into your skull while the other pops out and falls along your cheek. Vision range is halved, and you have disadvantage on ranged attacks.
4	Your lungs flap out of your throat. Take 1 point of exhaustion. If your rage lasts 4 or less consecutive rounds, this point of exhaustion is lost when your rage ends.
5	Your liver is exposed. Gain vulnerability to piercing damage.
6	Your body structure destabilizes. Gain vulnerability to force damage.
7	An artery bursts. At the start of your rage, take 2d10 piercing damage and an additional 3 piercing damage each turn until your rage ends.
8	Your eardrums are turned inside out. You are deafened.
9	A spout of blood shoots continuously out of the top of your head. At the beginning of your turns, make a DC 10 Constitution saving throw. On a failure, take 1d10 piercing damage.
10	Your higher brain functions shut down. You have disadvantage on Wisdom and Intelligence checks and saving throws and cannot speak or comprehend any languages.
11	You may roll on the side effects table twice and use either result.
12	No side effect.

Flux Endowment

Beginning at 6th level, your body begins to adapt to the effects of your Warp Spasm as you learn how to use your shifting physiology to keep yourself alive. When you enter your Warp Spasm Rage, roll a number of d10 dice equal to half your barbarian level, rounded down, and add the resulting number as temporary hitpoints for the duration of your rage. When the last temporary hitpoint from this feature is lost, all creatures within 5 feet of you must make a DC 14 Strength saving throw or be pushed back 5 feet and knocked prone.

Flux Overdrive

Beginning at 6th level, your rage grants you the ability to push your body beyond its absolute limits, at a potentially deadly cost. While raging, you are now able to cast a special version of Freedom of Movement on yourself as a bonus action once per day. In addition to the spell's normal effects, for 1d4 turns you also gain an extra 10 feet of movement and a +3 bonus to all attack rolls. All other effects of this spell end when your rage ends. After this spell is cast, your body structure becomes dangerously unstable, a condition known as Warp-Wracked. While Warp-Wracked, the following changes occur:

• Any loss of hitpoints will also reduce your hitpoint maximum.
• If you are reduced to 0 hitpoints in this condition, your death save DC now equals 10+your rage bonus. 
• If your hitpoint maximum is reduced to 0 in this condition, you automatically die. 
• The moment you die in this condition, any creature within 30 feet of your corpse must make a DC 16 Dexterity saving throw or suffer 10d12 bludgeoning damage as your Warp-Wracked form detonates, taking half damage on a save.

Taking a short rest will end this condition, but not restore your maximum hitpoints. Taking a long rest will reset your maximum hitpoints to their normal value.

Warp Strike

Beginning at 10th level, your battle prowess gives you a level of control over the nature of your rage-warped form, as well as the ability to inflict others with the side effects of your rage. You gain the ability to Warp Strike 3 times per day. On a successful attack against an enemy, you may either choose to reroll a Warp Spasm effect of your choice currently active on yourself or to confer a negative effect to the enemy struck by your attack, rolled on the Side Effect table. These effects end when your rage ends.

Flux Mastery

Beginning at 14th level, you have mastered the change brought on by the Warp Spasm. Once per rage, as a bonus action you may either roll an additional Warp Spasm effect on yourself, allowing for 3 simultaneous active Warp Spasm effects, or you may reroll the currently active side effect for your rage.