2 EARTH Machine monsters
If this card is Link Summoned: You can add 1 Ancient Gear monster or 1 Geartown from your Deck to your hand. You can target 1 Spell Trap you control and 1 face-up monster your opponent controls; destroy that card you control, and if you do, change that opponent s monster s ATK DEF to 0 until the end of this turn. You can only use each effect of Ancient Gear Ballista once per turn.