Elemental Warrior

Elemental Warriors are fighters who harness the raw power of the natural elements to enhance their combat abilities. By attuning themselves to one of the four elemental forces—Earth, Air, Fire, or Water—they gain unique powers that reflect the nature of their chosen element. Whether channeling the unyielding strength of Earth, the swift and elusive nature of Air, the destructive force of Fire, or the adaptive properties of Water, Elemental Warriors bring a versatile and powerful new dimension to the battlefield.

Elemental Style

When you choose this archetype at 3rd level, you learn a magical combat style that harness the power of one of the four elements. Choose one of the following options. 

Air Style
You learn the gust cantrip.
You can speak, read and write Auran.
Your movement speed increases by 10 feet, and your jump distance is doubled. Additionally, you can use Dexterity instead of Strength for the attack and damage rolls with any weapon that lacks the heavy property.

Earth Style
You learn the mold earth cantrip.
You can speak, read and write Terran.
When you hit a creature with a weapon attack with a heavy weapon you can attempt to shove it, provided that the creature is no more than one size larger than you. Additionally, bludgeoning, piercing, and slashing damage that you take from non-magical weapons is reduced by an amount equal to your proficiency bonus. 

Fire Style
You learn the control flames cantrip.
You can speak, read and write Ignan.
You weapon attacks deal an additional 1d4 fire damage, and you have resistance to fire damage. 

Water Style
You learn the shape water cantrip.
You can speak, read and write Aquan.
You gain a +2 bonus to AC, while you aren't wearing a shield or heavy armor. Additionally, you have a swimming speed equal to your walking speed and you can hold your breath for a number of minutes equal to 10 + Constitution modifier (minimum of 10 minutes).

Saving Throws. Some of the spells and features granted by this subclass require your target to make a saving throw to resist the effects. The saving throw DC is calculated as follows:

Elemental save DC = 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice)

Signature Move

At 7th level, you learn a secret technique that utilizes your element to overpower your foes. You gain one of the following bonus actions depending on your elemental style. At 15th level when you evolve your Elemental Style, you gain access to an additional signature move depending on your choice of advanced style.

Air Style (Advanced: Lightning/Mist)
Wind Dash: As a bonus action on your turn you take both the Dash and Disengage action. You can use this feature a number of times equal to your proficiency bonus, and you regain all uses on a short rest.

Earth Style (Advanced: Magma/Thorns)
Stone Shield: As a bonus action you can gain temporary hit points equal to your constitution modifier + your fighter level. You can use this feature a number of times equal to your proficiency bonus, and you regain all uses on a short rest. 

Fire Style (Advanced: Magma/Lightning)
Ignite Flame: When you hit a creature with a weapon attack on your turn you can use your bonus action to set them aflame for up to 1 minute. The burning target sheds bright light in a 10-foot radius and dim light for an additional 10 feet. At the beginning of each of its turns the target takes 1d6 fire damage. The target or a creature within 5 feet of it can use an action to extinguish the flames. The effect also ends if the target is submerged in water. You can use this feature a number of times equal to your proficiency bonus, and you regain all uses on a short rest.

Water Style (Advanced: Mist/Thorns)
Ebb and Flow: When you take the Dodge action on your turn you can use your bonus action to make yourself reactive. You can use a reaction to make a weapon attack against any creature that misses you with an attack, and you can take one reaction on every turn in combat until the beginning of your next turn. You can use this feature a number of times equal to your proficiency bonus, and you regain all uses on a short rest.

One With the Elements

At 10th level, you learn to embody the power of your chosen element. You can cast one of the following spells depending on your Elemental Style. At 15th level when you evolve your Elemental Style you gain access to an additional investiture depending on your choice of advanced style.

Air Style (Advanced: Mist/Lightning)
You can cast the investiture of wind spell. Once you use this feature you must finish a short or long rest before you can use it again.

Earth Style (Magma/Thorns)
You can cast the investiture of stone spell. Once you use this feature you must finish a short or long rest before you can use it again.

Fire Style (Advanced: Magma/Lightning)
You can cast the investiture of flame spell. Once you use this feature you must finish a short or long rest before you can use it again.

Water Style (Advanced: Mist/Thorns)
You can cast the investiture of ice spell. Once you use this feature you must finish a short or long rest before you can use it again.

Advanced Style

At 15th level you've mastered your elemental style to a degree where you can combine it with one of the other elements creating an even more powerful elemental style. You can speak, read and write Primordial and all its dialects (Aquan, Auran, Ignan and Terran). Choose one of the following options. This style replaces your former Elemental Style. 

Lightning Style
Prerequisite: air or fire style 
You learn the gust and control flames cantrips.
Your movement speed increases by 30 feet and your jump distance is tripled. You can jump off of the wind itself, treating the thin air as a solid surface for your jump allowing you to make a standing jump in the middle of the air. You can jump off the air twice before having to land. You can use Dexterity instead of Strength for the attack and damage rolls of all weapons that lack the heavy property. Whenever you hit a creature with a weapon attack you deal an additional 1d10 lightning damage, and you have resistance to fire and lightning damage.

Thorns Style
Prerequisite: earth or water style
You learn the mold earth and shape water cantrips.
You gain a +2 bonus to AC, while you're not wearing heavy armor. You have a swimming speed equal to your walking speed and you can hold your breath for a number of minutes equal to 10 + Constitution modifier (minimum of 10 minutes). When you hit a creature with a heavy weapon you can attempt to shove the target, provided that the creature is no more than one size larger than you. Also, bludgeoning, piercing, and slashing damage that you take from non-magical weapons is reduced by an amount equal to your proficiency bonus. 

The first time you hit a creature with a weapon attack on a turn, a writhing mass of thorny vines sprouts from the ground beneath the target, and the target must succeed on a Strength saving throw or be restrained by the magical vines for 1 minute. If the target succeeds on the save, the vines shrivel away. While restrained by this effect, the target takes 1d6 piercing damage at the start of each of its turns. A creature restrained by the vines or one that can touch the creature can use its action to make a Strength check against your DC. On a success, the target is freed.

Magma Style
Prerequisite: earth or fire style
You learn the mold earth and control flames cantrips.
When you hit a creature with a weapon attack you deal an additional 1d6 fire damage and 1d6 bludgeoning damage and you can attempt to shove the target. Bludgeoning, piercing, and slashing damage that you take is reduced by an amount equal to your proficiency bonus, and you have resistance to fire damage. If a creature hits you with a melee attack, it takes fire damage equal to twice your proficiency bonus.

Mist Style
Prerequisite: air or water style
You learn the gust and shape water cantrips.
You gain a +3 bonus to AC, when you arent wearing a shield or heavy armor. Your movement speed increases by 15 feet, and your jump distance is doubled. You have a swimming speed equal to your walking speed, you can move across water as if it were solid ground and you can hold your breath indefinitely as long as you're conscious. You can use Dexterity instead of Strength for the attack and damage rolls of all weapons that lack the heavy property.

Additionally, you gain access to an additional Signature Move and One with the Elements depending on your new style. 

Elemental Surge

At 18th level, when you use your Action Surge class feature you also create one of the following effects depending on your Elemental Style.

Lightning Style
Lightning Arc: At the end of your turn bolts of lightning arcs between all creatures you hit with a weapon attack on this turn. A target can be a creature or an object and can be targeted by only one of the bolts. All targets must make a Dexterity saving throw. On a failed save, a creature takes 6d10 lightning damage and is stunned until the end of your next turn. On a successful save, it takes half as much damage and isn't stunned.

Magma Style
Floor is Lava: The ground in a 10-foot radius around you becomes molten lava. The radius moves with you and any molten ground remains molten until the end of your next turn. When the lava appears, each creature, except you, standing in it must make a Dexterity saving throw. On a failed save, a creature takes 6d10 fire damage and burn. On a successful save, it takes half as much damage and doesn't burn. A creature, that isn't you, must also make this saving throw when it enters the lavas area for the first time on a turn or ends its turn there. A burning target sheds bright light in a 10-foot radius and dim light for an additional 10 feet. At the end of each of its turns, the target repeats the saving throw. It takes 2d10 fire damage on a failed save.

Thorns Style
Poison Sting: The ground in a 30-foot radius centered on you twists and sprouts hard spikes and thorns that lasts until the beginning of your next turn. The area becomes difficult terrain for all creatures except you. When the spikes and thorns appears, each creature, except you, in the area takes 1d6 piercing damage and must make a Constitution saving throw. On a failed save, a creature takes 6d10 poison damage and is poisoned for one minute. On a successful save, it takes half as much damage and isn't poisoned. A creature also takes 1d6 piercing damage and must make this saving throw when it enters the area for the first time on a turn or ends its turn there. When a creature moves into or within the area, it takes 1d6 piercing damage for every 5 feet it travels.

Mist Style
Freezing Mist: An icy mist spreads from you in a 20 foot radius. The mist spreads around corners and is heavily obscured for all creatures except you. The mist moves with you and disperses at beginning of your next turn. When the mist appears, each creature in it must make a Constitution saving throw. On a failed save, a creature takes 6d10 cold damage and its movement speed is halved until the end of your next turn. On a successful save, it takes half as much damage and its movement isn't halved. A creature must also make this saving throw when it enters the mists area for the first time on a turn or ends its turn there.