This collage of firespinning shows the creative power of a long exposure. With the shutter open, the camera is able to capture the complete movement of the firespinner, giving this feeling of flow and simplicity to the image.
I would choose gravity.I can repel to push them far away along with making them hit objects, attract to get closer to the enemy and cancel out their long range attacks or increase their gravity potential so they cant move and break their bones slowly.
Light Painting Photography in Nature and Cities by Vitor Schietti I've done plenty of steel wool long exposures, I even asked my high school girlfriend to prom by using steel wool and light painting. But these add a new element to it and I love it.