Master of lightning

This is a pretty powerful subclass.

Blast of lightning

Starting at 1st level, as a bonus action after you cast a spell of first level or higher, you can force a creature of your choice within 60ft of you to make a dexterity saving throw against your spell save DC or take lightning damage equal to half your sorcerer level (minimum 1).

Control lightning

Starting at 6th level, when you cast a spell that does lighting damage you can have the lighting jump from your blast and force a creature within 20ft of the area of affect or within 20ft the target to make a dexterity saving throw against your spell save DC or take xd6 lightning damage were x is 1/4 your sorcerer level rounded down. You can use this a number of times equal to your charisma modifier(minimum 1).

In addition, you gain resistance to lightning damage.

Become lightning

At 14th level, you gain the ability to temporarily become lightning. As a action you can transform into a bolt of lightning and blast over to a point that you can see within 60ft of you. Each creature within 5ft of the line path that you take to make a dexterity saving throw against your spell save DC or take 4d8 lightning damage or half as much on a successful one. The path you take must be a strait line. You regain use of this feature once you finish a long rest. Any time before you regain use of this feature you may spend 5 sorcery points to use it.

Lightning body

Beginning at 18th level, you can channel the power of raw lightning. As a action you can spend 7 sorcery points to take on form of lighting. Your eyes glow a bright blue and wight and shed dim light out 10ft. Lightning arcs from your body. Any creature that starts and ends its turn within 10ft of you will take lightning damage equal to your sorcerer level. While in this form you can use your action to send a of lightning that is 60f long and 5 feet wide. Each creature in the line must make a dexterity saving throw against your spell save DC or take 8d8 lightning on a failed save or half as much on a successful save. While in this form you can't cast spells of 3rd level or higher and you can't concentrate on spells. Finaly, as a bonus action on each of your turns you can teleport 30ft to a unoccupied space you can see. You remain in this form for 1 minute or until you are unconscious. You can't use this feature until you finish a long rest.

In addition you gain immunity to lightning damage.