Path of the Earthshaker

These barbarians have learned to use seismic energy to shape their terrain to their advantage. The strongest of these are capable of bringing down cities and they are widely feared

Seismic Buildup

Starting when you choose this path at 3rd level, while raging when you take 5 or more damage in one turn, you gain one quake counter. You can replace a attack while raging, to pay 4 quake counters to perform one of the options below

• Collapse Earthquake. Every creature within 10 ft of you has to make a Dexterity saving throw or take 1d12 bludgeoning damage and be stunned. They take half damage and aren’t stunned on a successful save. This damage increase to 3d12 at 6th level and 5d12 at 17th level.
• Volcanic Earthquake. You create lava on ground that you can see within range. Until your rage ends ends, the lava fills a 10 foot cube. Any creature in the lava’s space when you activate this must succeed on a Dexterity saving throw or take 2d8 fire damage and half as much damage on a successful save. A creature must also make the saving throw when it moves into the lava’s space for the first time on a turn or ends its turn there.

  The lava ignites flammable objects in its area that aren’t being worn or carried.

  The abilities damage increases to 4d8 at 6th level and to 6d8 at 17th level.

•  Explosion Earthquake, Every creature within 30ft of you must make a Constitution saving throw or they take 2d6 bludgeoning damage and 2d6 bludgeoning  damage. They take half damage on a successful save. This does double damage to objects and structures. The damage increases to 4d6 fire and 4d6 thunder at 6th level and 6d6  fire and 6d6 thunder damage at 17th level.

When any of your abilities calls for a saving throw, use your Seismic DC.

Seismic DC = 8 + proficiency bonus + Constitution modifier

Immovable Stance

Beginning at 6th level, you can’t be knocked prone or moved unless you want to. All of your abilities that deal bludgeoning damage are considered magical in order to overcome resistance. 

Seismic Imbued Strikes

Beginning at 10th level, you can imbue your attacks with seismic energy. Once per turn, when you make an attack with advantage because of your Reckless Attack feature, you can deal an extra 2d10 force damage on a hit and the target has to succeed on a Strength saving throw against your Seismic DC or have their movement speed halved and they can't take the dash action until the end of your next turn. This applies to any burrowing, climbing, flying, and swimming speed that they have.

Presence of the Earthshaker

Starting at 14th level, when a hostile creature starts it turn with 30ft of you while raging, it must succeed on a Strength save against your Seismic DC or fall prone and take a cumulative 1d4 penalty to all damage rolls and take 1d4 cumulative bludgeoning damage at the start of your turn. This damage  reduction and damage last for 1 minute.