This card can be used very offensively. You can use it to drop and revive a Six Samurai such as Yaichi who used his effect to destroy a card on your opponent's side of the field, thereby negating the part of the effect that prevents him from attacking. You can also use it on a Six Samurai who already attacked to allow them to attack again, such as allowing "Grandmaster of the Six Samurai" to hit your opponent for over a quarter of his/her Life Points.
A devastating combo with this is to send "The Six Samurai - Nisashi" during the Battle Phase to revive him another time, creating a very easy OTK if combined with "Grandmaster" and "Great Shogun Shien" (2100 + 1400 + 1400 + 1400+ 1400 = 7,700), or at least dealing 5600 + whatever other Six Samurai card you use.
This card can also be used defensively by chaining it to an Opponent's card that targets one of your "Six Samurai".
This card can work very well if you combine it with "The A. Forces". An OTK or even FTK with this combo is to summon "The Six Samurai - Zanji", then "Grandmaster of the Six Samurai" and then summon Great Shogun Shien. Then you have them all attack your opponent, then you use "Cunning" to send away "Zanji" or "Grandmaster" and have that one attack again.
Use this card when you draw only 1 copy of either Gateway of the Six or Six Samurai United and have only one Six Samurai. Play the continuous spell, summon the monster, play cunning to re-summon it, giving you the counters needed to do a search for another Six Samurai or draw 2 cards.