Pocket of Sand
Wondrous Item, rare
Sometimes there's just not any dirt on the ground. Fortunately, you always carry sand with you. The perfect tactical weapon for any fighter, it is coarse, rough, and irritating, and gets everywhere.
This extra-dimensional pocket can be attached to a garment to provide easy access to a handful of sand. Attaching the Pocket of Sand to or removing it from a garment requires an action. The pocket is large enough to hold one handful of sand, and weighs 1 lb.
Additional contents may not be added to the Pocket of Sand. Attempting to do so results in the item simply falling out. If the pocket is pierced or torn, it ruptures and and is destroyed, and its contents are scattered in the Elemental Plane of Earth. Sand may only be manually retrieved (ie, sand cannot be poured from the pocket). If the pocket is turned inside out nothing happens, but the pocket must be put right before it can be used again.
Placing a Pocket of Sand inside an extradimensional space created by a handy haversack, portable hole, or similar item instantly destroys both items and opens a gate to the Astral Plane. The gate originates where the one item was placed inside the other. Any creature within 10 feet of the gate is sucked through it to a random location on the Astral Plane. The gate then closes. The gate is one-way only and can't be reopened.
Whenever a melee attack is made against you, you may use a reaction to retrieve a handful of sand from the Pocket of Sand and make a melee attack against the attacker using either your Dexterity or Strength (your choice). The target must succeed on a Dexterity saving throw against your attack roll total. On a failure, the target is blinded until the end of its next turn. (A blinded creature can't see and automatically fails any ability check that requires sight. Attack rolls against the creature have advantage, and the creature's attack rolls have disadvantage.)
Constructs, creatures without eyes, or creatures that do not rely on sight (for example, one possessing the blindsight ability) are unaffected by the sand.