Void Bulwark

You conjure up a wall of endless darkness on the ground at a point you can see within range. You can make the wall up to 20 feet long, 10 feet high, and 5 feet thick, and it vanishes when the spell ends. 

Any enemies that move within 5ft of the wall has a chance of being lashed by void tentacles and being grappled (Roll a d20 above 10 they are grappled below they are not grappled), they must make a strength saving throw to break out of the Grapple against your spell save DC.

• A grappled creature’s speed becomes 0, and it can’t benefit from any bonus to its speed.
• The condition ends if the Grappler is incapacitated.
• The condition also ends if an Effect removes the grappled creature from the reach of the Grappler or Grappling Effect, such as when a creature is hurled away by the Thunderwave spell.