You gain 2d4 + 4 Temporary Hit Points.
Using a Higher-Level Spell Slot. You gain 5 additional Temporary Hit Points for each spell slot level above 1.
You attempt to interrupt a creature in the process of casting a spell. The creature makes 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 you to a point you choose within range and then blossoms with a low roar into a fiery explosion. Each creature in a 20-foot-radius Sphere centered on that point makes a Dexterity saving throw, taking 8d6 Fire damage on a failed save or half as much damage on a successful one.
Flammable objects in the area that aren't being worn or carried start burning.
Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.