Elemental HERO Thunder Giant (SGX1-ENA22) (Speed Duel GX: Duel Academy Box)

"Elemental HERO Sparkman" + "Elemental HERO Clayman" Must be Fusion Summoned and cannot be Special Summoned by other ways. Once per turn: You can discard 1 card to target 1 face-up monster on the field with original ATK less than the ATK of this card; destroy that target.