*Reaction, which you take when you see a creature within 60 feet of yourself casting a spell with Verbal, Somatic, or Material components
You attempt to interrupt a creature in the process of casting a spell. The creature must make a Constitution saving throw. On a failed save, the spell dissipates with no effect, and the action, Bonus Action, or Reaction used to cast it is wasted. If that spell was cast with a spell slot, the slot isn’t expended.
A bright streak flashes from your pointing finger to a point you choose within range and then blossoms with a low roar into an explosion of flame. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 lightning damage on a failed save, or half as much damage on a successful one.
The fire spreads around corners. It ignites flammable objects in the area that aren't being worn or carried.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.
Make a melee spell attack against a creature you can reach. On a hit, the target takes 3d10 lightning damage.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d10 for each slot level above 1st.