Fractured Soul

Asmodeus has a piece of your soul. Whenever you cast a non-cantrip spell your soul to infuse it with hellish energy.

You can add +1 to your spell DC OR +1 to spell attack, depending on the spell, OR +1 to each damage die you roll for spell damage.

Whenever this happens you roll a d20. If the result is equal or less than the spell's level, you can't control the energy and the spell miscasts. The DM randomly decides upon one character in the spell's reach. This character is hit with the magic as if you were targeting it with a natural 20 hit roll