2 Machine monsters Cannot be used as Link Material. You can only use 1 of the following effects of "Double Headed Anger Knuckle" per turn, and only once that turn. ● During the Main Phase (Quick Effect): You can send 1 monster from your hand or field to the GY, then target 1 Level 10 Machine monster in your GY; Special Summon it in Defense Position, but negate its effects. ● If this card is in your GY: You can send 1 card from your hand or field to the GY; Special Summon this card.