Catch Lightning

When you cast this spell the affected creatures body arcs with lightning. for the duration of the spell any creature that enters or starts its turn within 5 feet of the target take lightning damage equal to your proficiency bonus.

When you cast this spell and each round for the duration of the spell the target can use their action to become a lightning bolt untill the end of their turn. When the target become a lightning bolt their movement does not provoke opportunity of attack. Any creature within 5 feet of them must make a Dex saving throw or take 4d10 lightning damage or half damage on a successful one. Each creature can only be hit once per the action.

Increase damage by 1d10 for each spell slot above 4th level.