Apparently you've never seen a stall, burn, G-Bind deck that doesn't attack. That means you have no use for Mirror Force, Cylinder, Swords, or anything else like that. Why clutter up your M/T zone or your hand, just get rid of it! As for your comment about no cards require that M/T's have to be in the Grave, that is not true, it is a rare occurance. I'll give examples or the cards, and the types or deck it's useful, some don't require it but it will be more effective, for getting cards in the Grave than just waiting to discard. Magican of Faith, (every deck) Cemetary Bomb, (Burn decks) Blasting the Ruins, (Burn deck) and Mask or Darkness (trap using, or any other deck). Those are just some examples.