The caster's soul becomes spiritually magnetic, a selected creature (which must have a soul) within sight of the caster. Each round, at the end of the caster's turn all affected creatures (including the caster) are pulled closer to each other by 5 feet.

Any creature two sizes different than the others is instead pulled 10 feet toward the others without pulling them.  Thus casting soul magnetism on a Huge creature by a Medium creature would cause the Medium creature to be drawn inexorably to the huge creature due to the mass difference.

At Higher Levels. At caster levels, 5, 9, 13 the number of targets increases by 1.

If the caster is between multiple targets the GM decides which direction the caster moves, or whether the forces of two opposing pulls mean that the caster does not move,