Hybrid reactives are part solid reactive, part pearl reactive. The pearlization helps it skid, the solid part helps it read the midlane. Kind of a blending of what most people associate with pearl balls and solid balls.
It's not exactly a new trick, the original red/black Vendetta was a solid/pearl mix. Dynothane put out quite a few of them before they became the big thing they are now (the Centrifugal Mass, High Energy, 44 Magnum, The Thing, and probably others were solid/pearl blends).
SH