Entropy Blast

You create a sphere of raw entropy and toss it to a point within range. Each creature within a 15 foot radius centered on that point must succeed on a Strength saving throw as a massive blackened void tears through creatures within its range, dealing 7d6 force damage, halved on success. If a creature takes damage from this spell, their speed is halved until the end of their next turn.

At Higher Levels: When you cast this spell with a spell slot of 4th level of higher, the radius of the spell increases by an additional 5 feet per spell level above 3rd.