Sylas's Psionic Binding

Target up to Three separate creatures and hurl a blast of Psionic energy at each creature within range attempting to disrupt their bodies nervous system and render them immobile. Make a ranged spell attack against the target(s). On a hit, the target takes 6D6 Psychic damage and their speed drops to 0 till the end of their next turn. You cannot target the same creature with more than one Psionic blast at the time of casting this spell. 

 Using a Higher-Level Spell Slot. When you cast this spell using a spell slot of 4th level or higher, the spell Targets 1 additional Creature for each higher spell slot expended.