It does not work.
Newton third law already says it: If the pistol can levitate something, it is exactly the same amount of force the wielder would carry. And no, even Andre the Giant cannot hold a falling person with one hand.
The second problem is the difference of energy and momentum. To move something, you need momentum, the product of mass and velocity.
The most powerful .357 Magnum bullet weighs 12 gram (let's say the villain
is serious). A falling body of 70 kg for half a second means it fell 1,25 m (0.5*g*t^2) and achieved a velocity of 5 m/s.
This means the body has now a momentum of 350 Ns. A bullet with the same momentum must have a velocity of 350 / 0.012 = 29 166 m/s which is as fast as a meteor.
Even if you accelerate a bullet to such speeds, it has a much, much smaller surface area than a sword or a shield. This means the velocity is not used to accelerate the body backwards, but to penetrate the sword/shield. There is also no option to prevent this because the bullet is faster than the internal sonic speed, it moves inside the sword molecules before they have time to yield.
The thing is that "small fast thing moves big slow thing" also occurs in comedies and comics because it looks funny. The reason is that it is funny because it does not occur. If the big mass is n times more heavy than the small mass, for every gain or loss of 1 m/s of the big mass the small mass must move n m/s slower.
Big mass protects. If I put myself on the ground, holding an anvil over my belly, you can send the most vicious badass with a sledgehammer to pound the anvil and exactly nothing will happen. If a truck and a car collides head on, the truck is moderately slowed and feels a small impact, the car in contrast will be completely destroyed and driven back.