Tempest Knight

This subclass uses the elements of Lightning and Thunder to buff itself and the weapons it wields to control the battlefield by harnessing the power of the storm itself.  

Tempest Armory

Tempest Weapon

At 3rd level you can conduct an hour-long ritual, you and a weapon of your choosing are now bonded; while bonded, you can not be disarmed and can summon said weapon to your hand at will. Your weapon also gets enchanted with the element of thunder, allowing you to deal additional damage to your target by 1d4.

(This increases to 1d6 at 9th level and again to 1d8 at 15th level)

Tempest Shield

At 3rd level you can use a reaction to buff your AC by 2. This can be done a number of times equal to your Constitution modifier per short rest. (Tempest Shield increases your AC by 3 at 10th level.

Tempest Armor

At 3rd level the Storm grants you resistance to both Lightning and Thunder from regular attacks, spells and effects that come with it. The resistances turn into immunities at level 17

Reflexes of The Storm

At 3rd level the Storm gives you its blessings in movement and reflexes. With it, your movement is increased by 10, and you are able to disengage from a fight as a bonus action. Also, you become proficient in initiatives and dexterity saving throws, allowing you to add your proficiency modifier to each.

 

Discharge

At 7th level and once per short rest and at the cost of an action, you can use the electrons in your body to make an electrical explosion, damaging all enemies within 15ft of you. All enemies within range must make a Dexterity Saving Throw of 8+Dex mod+proficiency. If the save fails, those within your radius take 2d10 lightning damage. If passed, they take half damage. If you are grappled or struck by Lightning from any source after Discharge has been used, you gain the passive trait of Recharge, which grants an extra but weaker use of Discharge. This second explosion is reduced to 2d6. (Damage increases at 12th level to 4d10/4d6 and 17th level to 6d10/6d6)

One with The Storm

At 10th level, you channel the storm within you, granting two boons. First boon allows you to change your weapon’s elemental damage type from Thunder to Lightning if you so choose, while under the effect of OWTS. Second boon increases your attack range by 10ft. This attack can be done equal to the amount of your proficiency modifier per short rest. (At 18th level, range increases to 20ft)

Torrential Critical

At 15th level, when you land a critical hit, you summon a storm to strike your target, dealing an extra 5d8 Thunder damage and 5d8 Lightning. (These do not get doubled)

Avatar of the Tempest

At 18th level, your affinity with the Storm grows to new heights. The Storm grants you a new form named The Avatar of the Tempest (TAT), which can be activated once per long rest as a free action. With this form, you can have these abilities:

The ability to cast Storm Sphere at 8th level as an action requiring no concentration and lasting throughout TAT duration. (can be done once per activation of the skill)

All enemies take 1d12 of Lightning and 1d12 Thunder damage if they start their turn within 10ft of you.

And gives you a fly speed equal to your movement speed. 

This ability lasts 3 turns before needing a long rest, and you are not affected by the effects of the Storm Sphere you cast, even if you are no longer in TAT form.