Air Wall

Air Wall was the unnamed Quirk possessed by Nine, who stole it from an unknown hero.

Description
Air Wall lets Nine to create circular shields made of compressed air to shield himself. To create this defense Nine needs to raise his hand in a particular direction at a time. These barriers can withstand powerful attacks such as Izuku's Delaware Smash Air Force and can be layer for greater protection.

Nine can also use the shield to blast people away or fire powerful bursts of pressurized air able to knock down and even stun the opponent.

Weaknesses
Although tough, the Air Walls are not indestructible, and can be destroyed with particularly powerful attacks.

Air Walls are only created in the direction Nine raises his hand, so agile enemies can maneuver to avoid the shield and attack unprotected areas.