Deep Magic Volume 2 (p.179)
Fist From Hell
1-level Evocation
Casting Time: 1 action
Range/Area: 60ft.
Components: Verbal, Somatic
Duration: Instant
Attack/Save: STR Save
Damage/Effect: Force
You create an arcane speck of light above a creature you can see within range. The speck turns into a portal from which a massive fiendish fist strikes down on the target. The target must make a Strength saving throw. On a failed save, it takes 2d10 force damage and is knocked prone. On a successful save, it takes half the damage and isn’t knocked prone.
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.
Available for: Warlock