Flight allows Christopher to levitate and fly at high speeds. He was seen carrying a giant ship while flying, but it is unknown if this is solely due to his strength or another capability of his Quirk.
His Quirk covers himself and whatever and or whomever he is in contact with inside an aerodynamic barrier that protects from heat, cold, and physical harm. He can control how much of what or whom the barrier protects.
The main weakness of the Quirk is that the more Christopher spreads his Quirk around someone and or something else, the less protection he has around himself.