[BOSH] Swordsmith of Shiranui

If this card on the field is sent to the Graveyard as a Synchro Material: You can add 1 "Shiranui" card from your Deck to your hand, except "Swordsmith of Shiranui". You can only use this effect of "Swordsmith of Shiranui" once per turn. If this card is banished: You can activate this effect; for the rest of this turn, Zombie-Type monsters you control cannot be destroyed by battle.