Hellish Rebuke

Casting Time: 1 reaction, in response to being damaged by a creature you can see Range: 60 feet Components: V,S Duration: Instantaneous
You point your finger and that creature is momentarily surrounded by hellish flames. The creature must make a dexterity saving throw. It takes 2d10 fire dmg on a fail, or half on a success.
When you cast this spell at higher levels, the damage increases by ldl0 for each lvl above 1st.