Dynamo

Dynamos have unique bodies that naturally generate, store, and conduct electricity. They use this talent to enhance their agility, empower their attacks, and achieve feats that can only be described as shocking.

This subclass was inspired by the League of Legends champion Zeri, owned by Riot Games. The avatar for the class is the in game icon for her ultimate ability, and I claim no ownership of it.

Fast Charging

Every 15 ft of movement you take on your turn generates 1 charge, up to a maximum number of charges equal to your proficiency bonus. Each charge you have stored when you begin your turn increases your walking speed by an additional 10ft. Charge can be expended for various electrifying effects. 

Discharge

When you make a weapon attack or unarmed strike, you can expend a number of accumulated charges to cause the attack to deal an additional 1d4 lightning damage, per charge expended. If the attack is a sneak attack, the target must make a constitution saving throw with a DC of 9, plus 1 for every additional charge spent. If they fail, they are incapacitated until the end of your next turn.

Superconductor

You gain immunity to lightning damage. When you would take lightning damage, you can use your reaction to gain 1 charge, and temporary hit points equal to half the damage negated. These hit points last until you complete a short rest.

Amped Up

While at 5 or 6 charges, you become amped up. While amped up, discharge empowered sneak attacks that expend 5 or more charges will cause their target to instead be stunned if they fail the constitution saving throw. Additionally, while amped up, you can spend a charge to take either the dash, disengage, or dodge action.

Power Surge

If you fall to 0 hit points, and thereby fall unconscious, and are currently amped up, the electricity built up in your body resuscitates you. You rise to your feet with 1 hit point, and take your turn immediately. The creature who was acting then finishes their turn if they haven't already. Your place in the initiative order is then changed so that you act after the same creature each round thereafter.

Once you use this feature, you must complete a long rest before using it again.