Electrons spinning around an atom's core in a certain and same direction, makes the atoms have magnetic energy due to electric current being generated by those actions. To completely make a person into a magnet, Kidd needs to direct each of BM's electron movement, and then place BM in the proximity of another magnet in order to interact, in this case it can be Kidd himself or it can be the planet since the planet is a big magnet due to electric current generated by whatever energy the planet generates! But i'm not intelligent yet since a cultured man is a man capable of forming a harem so i'm not at that level yet root for me!