Magnetic: Bracelets

As the machine’s magnets ramped up, the bracelet didn't just pull; it vibrated with a frequency that bypassed his skin and resonated in his marrow. A blinding flash of violet light filled his vision. When the technician pulled the bed out, the room was empty.

The (a particle accelerator, a power plant, or the North Pole) MAGNETIC BRACELETS

I can then write the next chapter of Elias's transformation. As the machine’s magnets ramped up, the bracelet

The hum of the MRI machine was a rhythmic, mechanical heartbeat. Inside the tube, Elias felt his wrist throb. He had forgotten to take off the copper-and-magnet bracelet—a cheap gift from a roadside mystic who promised it would "align his frequencies." As the machine’s magnets ramped up

The (a rival magnet-user, a sentient field, or a government agency)