You summon a medium-sized skull resembling that of a dragon that takes up an unoccupied space within 10 feet of you. The skull is undead, with an AC of 10 and hitpoints equal to 5x your Intelligence modifier. You can use your bonus action to move it up to 30 feet. The spell ends early if the skull ever gets more than 60 feet away from you. Same if all the skulls are destroyed.
As an action on each turn, you can command the Blaster to make an energy beam attack in a straight line 60 feet long and 5 feet wide. Each creature in the area of the beam must make a dexterity saving throw. On a failed save, the creature takes 4d4 force damage (You can make it necrotic if you wanna go even more with necromancy) and half as much on a successful save.
Casting the spell again dissipates the current summoned skulls.

Casting At Higher levels;
For each level cast above the first, you may summon an additional skull. Taking an action to make an energy beam attack, commands every blaster to do so.