Skidmark raised his hands, and then swept them in a downward motion.  Twin shimmers not dissimilar to the heated air you saw above a hot road blasted towards the crowd.  Where the shimmers touched the ground, they changed the color of the flooring, creating bands of glowing ground six or seven feet wide.  After swirling for a moment, the colors settled into a gradient, stretching from violet on one side of the line to a pale blue on the other side.

The people who found themselves in the middle of the effect were dragged towards the blue side, as if they were standing on a steep slope.  The crowd roared, and began pushing people towards the effect.  Anyone who touched the purple side was caught with a greater force, dragged through to the blue side and cast towards the bulk of the crowd, sliding on the ground with enough force to stagger anyone they ran into.  The blue side seemed weaker, with anyone stepping on it finding strong resistance, as if they were trying to move against a strong headwind on oil-slick ground.  Only a handful of people made it out without being pushed back by the effects of Skidmark’s power or by the crowd that ringed the area.

Skidmark repeated the process to draw what I realized was a crude square in the middle of the mall, the ‘blue’ sides facing inward.  As he layered his power over the same area, the colors of the effect became darker, the ground below less visible and the effects on the people were all the more violent.  The blue sides had become dark blue, and instead of simply pushing against those who touched them, they threw people back towards the center of the ring.