You create black, inky shards from the endless void, which you unleash in a sphere with a diameter of 150 feet, centered at a point within the spell's range. Each creature in that sphere must succeed on a DEX saving throw. On a failed saving throw, they take 10d10+20 necrotic damage, and if they succeed the saving throw they instead take 10d10+20 necrotic damage halved. As long as the spell is still active, the caster can use their bonus action to deal an additonal 5d12 necrotic damage to every creature who failed the DEX saving throw.