Eldritch Bead

You summon 4 beads of energy. The beads circles around your wrist for the duration of the spell. while you have these beads you can use an action in your turn to release any number of these beads which detonates  at a point within 60 ft of you each of these beads blasts in an area of radius of 10ft. Each creature within this area makes a Dexterity saving throw against your spell save DC. On a failed save they take 3d8 points of force damage halved on a successful save. if multiple bead's blast overlaps an area the damage increases by 1d8 for each bead affecting the area.

At higher levels. When you cast this spell at 4th level or higher you can either choose to make an extra bead for each level or to increase the damage of each bead by 1d8.