Card Rulings:Legendary Six Samurai - Shi En

(TCG Rulings)

The effect to negate a Spell/Trap Card can be activated during the Damage Step.
It can be activated during each player's turn.
If this card is no longer face-up on the field when the effect to negate a Spell/Trap Card resolves, the Spell/Trap Card is still negated.
If this card is attacked while face-down and would be destroyed by the battle, you can destroy another face-up "Six Samurai" monster you control instead.