The video has been shared on many social media platforms, with the drone being called a 'levitating' sword. However, levitation requires a passive force like magnetism whereas the sword-like drone is equipped with four rotors that keep it suspended in the air and also enable it to fly around.
As can be seen in the image above, the sword has four symmetrically placed rotors — front, back, right, and left — generating enough torque to get it to lift off the ground, hover, and fly around. The owner controls it with a controller placed on his left palm and forefinger, which allows them to send the drone flying in a certain direction with 'gestures'.
Did he/she really build it? It is very unlikely they did, as there are similar products that have been shared on social media platforms before. Notable is a product on Amazon which does look nearly identical to the one shown in the video: Flying Sword RC Glider. So even if the OP really did build this particular "sword", it is not a unique idea. As other Redditors were quick to point out, highly similar drones can be had from xiaohongshu.com among other options.
That being said, we recently covered an engineering marvel that does seem to have some unique thinking behind it: a DIY engineer in China built a drone that can fly, walk, and swim. To add to the marvel, the small amphibious drone was 3D-printed.