Path of the Storm Herald (extended)

(out of Xanathars Guide to Everything pg.10) "All barbarians harbor a fury within. Their rage grants them superior strength, durability, and speed. Barbarians who follow the Path of the Storm Herald learn to transform that rage into a mantle of primal magic, which swirls around them. When in a fury, a barbarian of this path taps into the forces of nature to create powerful magical effects. Storm heralds are typically elite champions who train alongside druids, rangers, and others sworn to protect nature. Other storm heralds hone their craft in lodges in regions wracked by storms, in the frozen reaches at the world's end, or deep in the hottest deserts."

They also could be honing their craft in the echo of mountains, girding against flatland gusts, or climbing bottomless canyons. 

Storm Aura

Starting at 3rd level, you emanate a stormy, magical aura while you rage. The aura extends 10 feet from you in every direction, but not through total cover.

Your aura has an effect that activates when you enter your rage, and you can activate the effect again on each of your turns as a bonus action. Choose desert, sea, tundra (from book, not listed here) canyon, mountain, plain (extended) Your aura's effect depends on that chosen environment, as detailed below. You can change your environment choice whenever you gain a level in this class.

If your aura's effects require a saving throw, the DC equals 8 + proficiency bonus + your Constitution modifier.

Canyon. When this effect is activated, each creature of your choice in your aura have their speed reduced by 5 ft. The speed reduced increases when you reach certain levels in this class, increasing to 10 ft. at 5th level, 15 ft. at 10th level, 20 ft. at 15th level, and 25 ft. at 20th level. This reduction lasts until the end of their next turn.

Mountain. When this effect is activated, each of your melee weapon attacks create a thunderous boom audible of 100 ft. Your melee weapon attacks deal 2 points of thunder damage on hit. The damage increases when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 10th level, 5 at 15th level, 6 at 20th level.

Plain. When this effect is activated, each creature of your choice in your aura have their speed increased by 5 ft. The speed increases when you reach certain levels in this class, increasing to 10 ft. at 5th level, 15 ft. at 10th level, 20 ft. at 15th level, and 25 ft. at 20th level. This increase lasts until the end of their next turn. 

Storm Soul

At 6th level, the storm grants you benefits even when your aura isn't active. The benefits are based on the environment you chose for your Storm Aura.

Canyon. You gain resistance to non-magical bludgeoning damage. You also gain a climbing speed equal to your walking speed.

Mountain. You gain resistance to thunder damage. Additionally, as an action, you can shout at such power that creatures in a 15 ft. cone in front of you are deafened and must make a constitution saving throw. On a fail, the target is additionally frightened of you until the end of your next turn. Unprotected flames are snuffed out and objects weighing less than 5 lbs are throw the distance of the cone. You can use this ability up to your constitution modifier (minimum of 1). You regain all expended uses upon a short rest. 

Plain. You gain a resistance to poison damage. Additionally you can hold your breath for 15 minutes.

Shielding Storm

At 10th level, you learn to use your mastery of the storm to protect others. Each creature of your choice has the damage resistance you gained from the Storm Soul feature while the creature is in your Storm Aura.

Raging Storm

At 14th level, the power of the storm you channel grows mightier, lashing out at your foes. The effect is based on the environment you chose for your Storm Aura.

Canyon. Whenever the effect of your Storm Aura is activated, the ground while you move become uplifted and turns into difficult terrain. At the end of your turn, creatures that are standing in the difficult terrain suffer piercing damage equal to your constitution modifier. 

Mountain. As an action while your Storm Aura is active, you can call upon the power of thunderous force to propel outwards from you. All creatures within your aura must make a Constitution saving throw or suffer thunder damage equal to half your barbarian level, are pushed back 15 ft. and are knocked prone. On a success, they are not pushed back or knocked prone and receive half damage.

Plain. While your Storm Aura is active, ranged attacks are at disadvantage when passing through your aura. As an action, you can call the winds around you to spiral upwards. Objects weighing less than 15 lbs. are lifted upwards and thrown 15 ft. in random directions. Other creatures within your aura while objects are being thrown must make a Dexterity saving throw or suffer bludgeoning damage equal to half your barbarian level.