Alufyx's Ice Knife Barrage

You create seven circles, each producing a finely crafted dagger of ice and flinging them at creatures within range. Make 7 ranged spell attacks against up to 7 targets of your choice within range. On a hit, the target takes 1d10 + your spell casting abilities bonus piercing damage. Hit or miss, each dagger then explodes in a frosty elemental burst. The target and each creature within 10 feet of each dagger take 4d6 cold damage or half as much with a successful Dexterity saving throw and there movement is reduced to half till the beginning of your next turn.