Ancient Gear Castle (SD10-EN023) - Structure Deck: Machine Re-Volt Unlimited

Each face-up Ancient Gear monster gains 300 ATK. Each time a monster(s) is Normal Summoned or Set, put 1 counter on this card. If you Tribute Summon an Ancient Gear monster, you can substitute this card for a Tribute(s), if the number of counters is equal to or greater than the number of required Tribute(s).