Deepend Lightning

Whether through blessing or curse, You are imbued with the power of the lightning's innate ability to control lightning (to an extent). As an action, you roll a Constitution saving throw (DC 15) to channel the energy and cast a lightning bolt. When casting the spell it deals 9d6 lightning damage, able to cast two times per long rest upon successes. (Second attack DC is increased to 20)

Uncontrolled: Upon failing, you are dealt 1d8 lightning damage and cannot channel anymore until after a long rest.