Magnetic force is the force of magnetic field on magnet, and the force of current on magnet. Magnetic force is the propagation of electromagnetic field, and the speed of electromagnetic field is the speed of light, so is the speed of magnetic force. Because its nature is not clear, whether there is a magnetic black hole is still unknown, and a strong enough magnetic field has not been observed. And if the magnetic force can't bend space-time, it won't form a magnetic black hole.