Hellish Rebuke
Source: Player's Handbook
Level 1 Evocation (Warlock)
Casting Time:f
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.