Yu-Gi-Oh! Spirit Monsters are a group of monsters that return to your hand at the end of the turn they were Normal Summoned or flipped face-up. This can be good because it means they will not be on the field during your opponent's turn.
DOUBLE DUTY "Limiter Removal" doubles the ATK of all your Machine monsters, but all that power comes with a steep cost. All the monsters affected by "Limiter Removal" are destroyed at the end of the turn. Since your monsters will be destroyed anyway, there's no reason not to use it with "Ruthless Denial" after you attack. This makes your opponent discard 1 card from their hand, giving you an even bigger edge! - click here for another Dueling Tip.