V'aaggi Tendrils

Description: You summon writhing tendrils of eldritch energy from the void, reaching out to ensnare your foes. When you cast this spell, dark tendrils emerge from a point you choose within range. Each creature within a 20-foot cube originating from that point must make a Dexterity saving throw. On a failed save, a creature takes 3d6 force damage and is restrained by the tendrils until the spell ends. A creature restrained by the tendrils can use its action to make a Strength or Dexterity check (target's choice) against your spell save DC. On a success, the creature frees itself.

Bonus Action: on your subsequent turns, you can move the tendrils up to 30 feet in any direction. Any creature that starts its turn within 10 feet of the tendrils or enters that area for the first time on a turn must succeed on a Dexterity saving throw or take 2d6 force damage.

     -Additionally, while you concentrate on this spell, you can use a bonus action to cause the tendrils to lash out at one creature restrained by them. The target must make a Dexterity saving throw, taking 2d6 force damage on a failed save, or half as much damage on a successful one. The target's speed is also halved until the end of its next turn.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.