Storm Martyr

Your patron is Kord’s champion, Ondyl, the great bronze dragon.

Amphibious

Beginning at 1st level, you can breathe both air and water.

Forge the Storm

Beginning at 1st level, you can use your bonus action to create a weapon made of pure lightning that persists until you use a bonus action to dismiss it.

This weapon has the range of its mundane counterpart, but does 1d8 lightning damage instead of bludgeoning, piercing, or slashing. You gain proficiency with this weapon while wielding it. You use your charisma modifier for attack and damage rolls. It is considered a magical weapon for the purpose of overcoming resistances.

This weapon improves over time as you grow more powerful, in the following ways:
5th level - you gain a +1 bonus to attack and damage rolls
9th level - you gain a +2 to attack and damage rolls, and when you make a critical hit against a creature, they must make a constitution saving throw against your spell save DC or be stunned until the end of your next turn
17th level - you gain a +3 bonus to attack and damage rolls, and your stunning ability is now available whenever you score any hit, not just a critical hit

If you have the Pact of the Blade feature, the weapon summoned from this feature is your pact weapon and can benefit from invocations that affect your pact weapon.

Static Fog

At 6th level, you add the spell fog cloud to your spell list. It is considered a Warlock spell for you. Whenever you cast it, you can use your bonus action to imbue the fog with the power of the storm. You can choose to force creatures within the fog to make a Constitution saving throw against your Warlock spell save DC or take 3d8 lightning damage, OR you can shock creatures to remove conditions from them, such as charmed, frightened, invisible, or stunned. You can also use this feature to remove 1 level of exhaustion from yourself or another creature until the beginning of your next turn.

Once you have used this feature, you cannot use it again until you finish a short or long rest, but you can continue casting fog cloud without the extra features.

Repulsion Breath

Starting at 10th level, you can use your action to breathe out a shockwave of energy in a 20-foot cone. Creatures in that cone must make a Strength saving throw against your Warlock spell save DC or be pushed 30 feet away from you.

You can use this feature a number of times equal to your Charisma modifier (minimum of 1). All expended uses are regained after you finish a short or long rest.

Eye of the Storm

Beginning at 14th level, you can use your action to summon a tumultuous storm in a 60-foot radius, centered on you. Creatures entering this storm for the first time or ending their turn inside its radius must make a Dexterity saving throw, taking 10d10 lightning damage on a failed save or half as much on a successful one.

You create an inner radius of 15 feet that is safe from the outer radius. Creatures attempting to enter this eye must make a Strength saving throw against your Warlock spell save DC, or be pushed 10 feet away from you.

Once you use this feature, you can’t use it again until you finish a long rest.