The Norse God Thor sometimes bestows a portion of his control over thunder and lightning to mortals who show great potential. Sometimes the children of great heroes are born with this power, but more often courageous mortals are blessed with it as a reward for great feats. As a result, there is no established school of thought for those blessed with these powers -- the few who have it are often too busy or too proud to come together and encode any core doctrine for how they should be used. Thus, it is often up to the individual to decide how to hone their newfound abilities -- and whether they should strengthen these powers to their greatest potential, or use them to supplement their already impressive fighting abilities. 

Disciple of the Storm

3rd-Level Way of the Old Storm Feature

You can channel thunderous power to magnify your presence and imbue your unarmed strikes with the essence of a mighty storm. You gain the following benefits:

Electric Personality. If you fail a Charisma (Intimidation) or Charisma (Persuasion) check, you can use your reaction to reroll the check, as you tap into the mighty presence of Thor. Once this feature turns a failure into a success, you can’t use it again until you finish a long rest.

Lightning Strike. When you damage a target with an unarmed strike, you can change the damage type to lightning or thunder.

Tongue of The Gods. You learn to speak, read, and write Celestial or one other language of your choice.

Good Conduit. You have resistance to lightning damage.

Bolt of Lightning

3rd-Level Way of the Old Storm Feature

You can channel destructive strikes of electricity, like those created by the storms you embody. When you take the Attack action on your turn, you can replace one of the attacks with a zap of electricity targeted at a creature that you can see within 30 ft. of you. Each creature within 10 ft. of that point (including the target) must make a Dexterity saving throw against your ki save DC, taking lightning damage equal to two rolls of your Martial Arts die on a failed save, or half as much damage on a successful one.

At 11th level, the damage of this feature increases to three rolls of your Martial Arts die.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest. While you have no uses available, you can spend 2 ki points to use this feature again.

Gone in a Flash

6th-Level Way of the Old Storm Feature

When you use your Step of the Wind, you can briefly move as fast as a bolt of lightning. You may immediately teleport up to 15 ft. to an unoccupied space you can see. If you choose to do this, a thunderous boom erupts from where you were previously standing. Any creature within 10 ft. of where you were standing must make a Constitution saving throw against your ki save DC, or become deafened for one minute. 

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

 

Aspect of the Tempest

11th-Level Way of the Old Storm Feature

The power of your tempestuous spirit now radiates from you, warding your allies or inspiring fear in your enemies. As a bonus action, you can create an aura of ancient power that radiates 10 feet from you for 1 minute. For the duration, you gain one of the following effects of your choice:

Frightful Presence. When you create this aura, and as a bonus action on subsequent turns, you can choose a creature within the aura. The target must succeed on a Wisdom saving throw against your ki save DC or become frightened of you for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a successful save.

Resistance. You and your allies within the aura have resistance to lightning and thunder damage.

Once you create this aura, you can’t create it again until you finish a long rest, unless you expend 3 ki points to create it again.

Lightning and Thunder Resistance Aura

You and your allies within the aura have resistance to lightning and Thunder damage.

Asgardian Aspect

17th-Level Way of the Old Storm Feature

Your Asgardian spirit reaches its peak. You gain the following benefits:

Augment Strike. When you use your Bolt of Lightning, you can spend 1 ki point to augment its shape and power. The strike of electric energy becomes either a 90 ft. line that is 5 ft. wide, or a 15 ft. radius sphere centered around a creature you can see within 60 ft. (your choice), and each creature in that area takes damage equal to four rolls of your Martial Arts die on a failed save, or half as much damage on a successful one.

Blindsight. You gain blindsight out to 10 feet. Within that range, you can effectively see anything that isn’t behind total cover, even if you’re blinded or in darkness. Moreover, you can see an invisible creature within that range, unless the creature successfully hides from you.

Explosive Fury. When you activate your Aspect of the Tempest, thunderous fury explodes from you. Choose any number of creatures you can see in your aura. Each of those creatures must succeed on a Dexterity saving throw against your ki save DC or take 3d10 thunder or lightning damage (your choice).