Phantom Knights' Sword

Activate this card by targeting 1 face-up monster on the field; it gains 800 ATK, also if that target would be destroyed by battle or card effect, you can destroy this card instead. When it leaves the field, destroy this card. You can banish this card from your GY, then target 1 "The Phantom Knights" monster in your GY; Special Summon it, but banish it when it leaves the field. You can only use this effect of "Phantom Knights' Sword" once per turn.