Path of the Thunder Beast

Barbarians who walk the Path of the Thunder Beast channel their rage through raw energy of lightning and thunder, transforming into fearsome warriors capable of unleashing the fury of the storm upon their enemies. This path enhances their physical prowess and grants them extraordinary resilience, allowing them to thrive amidst the chaos of battle and  evoke the primal power of thunderstorms.

Stormborn Fury

Once per rage, when you take damage, you can choose to release a burst of thunderous energy. All creatures within 10 feet of you must make a dexterity saving throw. The DC is 8+ your proficiency bonus + your constitution score. On a fail, they take 2d6 thunder damage.  This damage increases to 3d6 at 10th level and 4d6 at 15th level.

In addition, they have resistance to Lightning and Thunder damage.

Thunderous Wrath

During rage, your melee weapon attacks deal an additional 1d8 lightning damage. If you score a critical hit, unleash a thunderous boom that echoes within a 30-foot radius; all creatures within range must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Constitution modifier) or be stunned until the end of your next turn.

Thunderstep

Once per rage, as an action, you can teleport up to 30 feet in a straight line before making an attack, leaving a thunderous burst in your wake. The area you vacated is subjected to a thunderous boom, forcing creatures within 5 feet to make a Dexterity saving throw or receive 2d8 thunder damage and be knocked prone.

Heart of the Storm

Once per long rest, you can transform into a living embodiment of storm energy for 5 minutes. During this time, you gain flying speed of 60 feet, and auras of crackling lightning surround you, causing creatures within 5 feet to take 1d8 lightning damage when they start their turn in the aura.