"Training Days, Part 2", known as "Certain-Kill Ninja Art! The Most Dreadful Ninja Appears" in the Japanese version, is the sixteenth episode of the Yu-Gi-Oh! ZEXAL anime. It first aired in Japan on July 25, 2011 and in the United States on March 24, 2012.
It's a Duel against Roku's former disciple, Kaze! Kaze draws his "Ninja" monsters, pinning Yuma down, but believing in the power of his friends, Yuma continues this battle even after Kaze Summons his Trump Card, "Number 12: Crimson Shadow Armor Ninja". However thanks to Roku and Astral, Yuma wins the duel.
Turn 4: Kaze
Kaze activates "Spy Attack", sending the "Aqua Armor Ninja" in his hand to the Graveyard to check Yuma's Set card, which is "Gagagaback". "Blade" attacks and destroys "Gagaga Magician" (Yuma 2600 → 1900). Kaze activates the effect of "Blade", detaching an Overlay Unit to allow it to attack again. "Blade" attacks and destroys "Dododo Warrior" (Yuma 1900 → 1500). As he controls a face-up "Ninja" monster, Kaze activates his face-down "Armor Ninjitsu Art of Rust Mist", which will halve the ATK of all Special Summoned monsters Yuma controls as long as it remains face-up. Yuma activates his face-down "Gagagaback", Special Summoning "Gagaga Magician" (1500/1000) and "Dododo Warrior" (2300/1900) from his Graveyard as a "Gagaga" monster was destroyed by battle this turn. Yuma takes 600 damage for each one (Yuma 1500 → 300) and their ATKs are halved (Gagaga Magician's ATK: 1500 → 750, Dododo Warrior's ATK: 2300 → 1150).
Turn 5: Yuma
Yuma activates "Gagagabolt", destroying "Blade" as he controls a face-up "Gagaga" monster. "Gagaga Magician" attacks directly" (Kaze 4000 → 3250). "Dododo Warrior" attacks directly, but Kaze activates the effect of the "Aqua Armor Ninja" in his Graveyard, banishing it to negate the attack. The effect of "Dododo Warrior" activates, negating Kaze's card effects until the end of the Damage Step (Dododo Warrior's ATK: 1150 → 2300). Thus, the effects of "Armor Ninjitsu Art of Rust Mist" and "Aqua Armor Ninja" are negated and the attack proceeds (Kaze 3250 → 950). Yuma Sets a card.
Kaze activates "Armor Ninjitsu Art of Alchemy", destroying "Armor Ninjitsu Art of Rust Mist" and "Armor Ninjitsu Art of Freezing" to draw two cards. Thus, the ATKs of "Gagaga Magician" and "Dododo Warrior" return to their original values and they may change their Battle Positions. Kaze Special Summons "Earth Armor Ninja" (1600/1200) in Attack Position via its own effect as he controls no monsters while Yuma does. Kaze then activates "Armor Ninjitsu Art of Revival", Special Summoning "Flame Armor Ninja" from his Graveyard (1700/1000) in Attack Position. He activates its effect, increasing its Level by 1 since it was Special Summoned. Kaze overlays his two Level 5 monsters to Xyz Summon "Number 12: Crimson Shadow Armor Ninja" (2400/1700) in Attack Position. "Crimson Shadow" attacks "Gagaga Magician", but Yuma activates his face-down "Guts Guard", changing the target to "Dododo Warrior" and preventing its destruction in battle this turn (Yuma 300 → 200).
Turn 7: Yuma
Yuma activates "Decrease", reducing the Level of "Dododo Warrior" by 2 until the End Phase. Yuma overlays his two Level 4 monsters to Xyz Summon "Number 39: Utopia" (2500/2000) in Attack Position. "Utopia" attacks "Crimson Shadow" (Kaze 950 → 850). Kaze activates the effect of "Crimson Shadow", detaching an Overlay Unit to prevent its destruction. Yuma activates the Quick-Play Spell Card, "Revenge Attack", allowing "Utopia" to attack again as it failed to destroy a monster in battle, with its ATK increases by 1000 (Utopia's ATK: 2500 → 3500). "Utopia" attacks and destroys "Crimson Shadow" (Kaze 850 → 0).