Vallon, the Super Psy Skyblaster

“2 Level 5 monsters During the Main Phase (Quick Effect): You can detach 1 material from this card, then target 1 face-up monster your opponent controls; change it to face-down Defense Position. If this card is sent to the GY: You can target 1 face-down card on the field; destroy it. You can only use each effect of "Vallon, the Super Psy Skyblaster" once per turn.”