Hellish Rebuke

Source: Player's Handbook (2024)

1st Level Evocation (Warlock)

Casting Time: Reaction(*) Range: 60 feet Components: V, S Duration: Instantaneous

The creature that damaged you is momentarily surrounded by green flames. It makes a Dexterity saving throw, taking 2d10 Fire damage on a failed save or half as much damage on a successful one. Using a Higher-Level Spell Slot.
The damage increases by 1d10 for each spell slot level above 1.