Activate only while there is a face-up "Elemental Hero Bubbleman" on the field. Change 1 face-up Attack Position "Elemental Hero Bubbleman" that you control and 1 face-up Attack Position monster your opponent controls to Defense Position. Tribute the "Elemental Hero Bubbleman" that was changed to Defense Position and Special Summon 1 "Elemental Hero" monster from your hand.