Leo, Luna and Devack's Duel

Leo, Luna and Devack's Duel was a Standard Duel between Leo and Luna, the latter of which joins in near the end, and Devack which took place outside the Tower of Cusillu, in the Yu-Gi-Oh! 5D's anime.

Prior Events
After Rally Dawson sacrifices himself to have Yusei Fudo win against Roman Goodwin, the other four Dark Signers, Misty Tredwell, Kalin Kessler, and two unknown Dark Signers appear. Roman decrees that each Signer will duel their respective Dark Signer counterpart for the fate of the world. The Dark Signer wearing black and yellow introduces himself as Devack and he holds Luna's "Ancient Fairy Dragon". As the Dark Signers leave, Jack Atlas catches a glimpse of the Dark Signer in black and orange. When he confronts her, she is revealed to be Carly Carmine.

The Signer team holds a strategy meeting. In order to prevent the Gate to the Netherworld from opening up, the four towers of the Ener-D reactor need to be shut down with each Signer's signature card. Luna heads to the tower of Cusillu to defeat Devack and get "Ancient Fairy Dragon" back, Yusei heads to the Tower of Ccapac Apu to settle things with Kalin, Akiza Izinski heads to the Tower of Ccarayhua to deal with Misty, and Jack heads to the Tower of Aslla piscu to help Carly.

As Tetsu Trudge gives Leo and Luna a ride, "Kuribon" tells Luna that the Duel Monsters Spirit World is in danger and at it's behest, Luna leaves for the Duel Monsters Spirit World. Yusei notices this and puts his duel with Kalin on hold.

At the Tower of Cusillu, Devack is angry at the fact Leo showed up instead of Luna, but Leo says he will be duelling in Luna's place and the duel commences, with Devack unleashing his Mark of the Monkey.

Featured Duel: Leo and Luna vs. Devack
Turn 1: Leo

Leo's hand contains "Level Mirroring", "Morphtransition", "Remake Puzzle", "Gadget Hauler" and "Pot of Avarice". Leo draws "Morphtronic Magnen" and subsequently Normal Summons it (800/800) in Defense Position. He then Sets a card ("Morphtransition").

Turn 2: Devack

Devack's hand contains "Magician Ape", "Fighter Ape", "Dark Tuner Dark Ape", "Dark Wave" and "Dark Matter". Devack draws "Magician Ape" and subsequently Normal Summons it (800/1200) in Attack Position. Devack then activates the effect of "Magician Ape" to discard another "Magician Ape" and take control of "Morphtronic Magnen". "Magician Ape" attacks directly (Leo 4000 → 3200).

In the Duel Spirit World, Luna notices staves pointed in the ground, and monkeys are wielding these staves. The staves themselves inflict a curse that throws the flow of time in reverse and they also capture duel spirits for their master "Zeman the Ape King". She saves a boy called "Tobias" who tells her the whole story. With this information, Luna is more determined than ever to free "Ancient Fairy Dragon".

Turn 3: Leo Leo draws "Morphtronic Magnen Bar" and subsequently Normal Summons it (100/100) in Defense Position. He then Sets a card.

Turn 4: Devack Devack draws "Fighter Ape". He then activates the effect of "Magician Ape" to discard "Fighter Ape" and take control of "Morphtronic Magnen Bar". Leo explains that due to the Defense Position effect of "Morphtronic Magnen Bar", none of Devack's monsters can attack. Devack then Tributes "Morphtronic Magnen Bar" in order to Tribute Summon "Fighter Ape" (1900/1200) in Attack Position. "Fighter Ape" then attacks directly, but Leo activates his face-down "Remake Puzzle" to destroy "Morphtronic Magnen" and end the Battle Phase as well as Special Summon "Morphtronic Magnen Bar" (100/100) from his Graveyard in Defense Position.

Turn 5: Leo Leo draws "Morphtronic Celfon" and subsequently Normal Summons it (100/100) in Attack Position. He then activates the Attack Position effect of "Morphtronic Celfon" to roll a die. Leo gets a three, so he looks at the top three cards of his Deck ("Junk Box", "Factory of 100 Machines" and "Morphtronic Remoten"). Leo finds "Morphtronic Remoten" among the picked up cards, so he Special Summons "Morphtronic Remoten" (300/1200) in Attack Position. The other picked up cards are then returned to Leo's Deck. Leo then activates "Level Mirroring" to make the Level of "Morphtronic Magnen Bar" the same as the Level of "Magician Ape" ("Morphtronic Magnen Bar": Level 1 → 3). Leo then tunes "Morphtronic Celfon" and "Morphtronic Magnen Bar" with "Morphtronic Remoten" in order to Synchro Summon "Power Tool Dragon" (2300/2500) in Attack Position.

Leo then activates the first effect of "Power Tool Dragon" to add a random Equip Spell Card from his deck to his hand ("Break! Draw!"). Leo then equips "Break! Draw!" to "Power Tool Dragon". Now whenever "Power Tool Dragon" destroys a monster in battle and sends it to the Graveyard, Leo can draw one card. If Leo uses this effect, three times, "Break! Draw!" will be destroyed. "Power Tool Dragon" attacks and destroys "Magician Ape" (Devack 4000 → 2500). Due to the effect of "Break! Draw!", Leo draws a card.

Turn 6: Devack Devack draws "Dark Tuner Dark Ape" and subsequently Normal Summons it (0/0) in Attack Position. He then activates "Dark Wave" to multiply the Level of "Fighter Ape" by -1 ("Ape Fighter": Level 5 → -5). Devack then dark tunes "Fighter Ape" with "Dark Tuner Dark Ape" in order to Dark Synchro Summon "Zeman the Ape King" (2500/1800) in Attack Position. Since "Dark Tuner Dark Ape" was used for a Dark Synchro Summon and sent to the Graveyard, Devack draws a card. He then activates "Closed Forest". Now all Beast-type monsters Devack controls will gain 100 ATK for each monster in his Graveyard.

In the Duel Spirit world, Luna and Tobias come across "Regulus", who is suffering under the effect of the Minus Curse. After removing the staff, "Regulus" comes to his senses and as an apology, offers to help Luna free "Ancient Fairy Dragon" from "Zeman the Ape King".

Turn 6: Devack

Devack has just activated "Closed Forest" and there are currently five monsters in Devack's Graveyard ("Zeman the Ape King": 2500 → 3000/1800). "Zeman the Ape King" attacks "Power Tool Dragon", but Leo sends "Break! Draw!" to the Graveyard to prevent "Power Tool Dragon" from being destroyed in battle (Leo 3200 → 2500). Devack Sets two cards.

Turn 7: Leo

Leo draws "Respect Synchron". He then activates the effect of "Power Tool Dragon" to add a random Equip Spell Card from his Deck to his hand ("Megamorph"). Leo then equips "Megamorph" to "Power Tool Dragon", intending to use it to double the ATK of "Power Tool Dragon". However "Megamorph" has no effect as both players' Life Points are currently equal. Leo's hand contains "Respect Synchron", "Gadget Hauler", "Pot of Avarice", and "Urgent Tuning". Leo switches "Power Tool Dragon to Defense Position (2300/2500).

Turn 8: Devack

Devack draws. "Zeman the Ape King" attacks "Power Tool Dragon". Devack then activates his face-down "Roaring Earth", which allows his monsters to inflict piercing damage. Leo sends "Megamorph" to the Graveyard to prevent "Power Tool Dragon" from being destroyed in battle, however "Zeman the Ape King" then inflicts piercing damage to Leo (Leo 2500 → 2000). "Roaring Earth" then reduces the ATK and DEF of "Power Tool Dragon" by 300 (Power Tool Dragon: 2300 → 2000/2500 → 2200). Devack Sets a card.

In the Duel Spirit World, Luna, Regulus and Tobias infiltrate Zeman's castle, disguised as soldiers who have "captured" Regulus. Luna requests that Zeman release Ancient Fairy Dragon from the Minus Curse. As he does so, their ruse is exposed and Zeman goes back on Luna's request.

Turn 9: Leo

Leo draws. He then activates the first effect of "Power Tool Dragon" to add a random Equip Spell from his Deck to his hand ("Double Tool C&D"). He then switches "Power Tool Dragon" to Attack Position (2000/2200) and equips it with "Double Tool C&D". Since it is currently Leo's turn, "Double Tool C&D" increases the ATK of "Power Tool Dragon" by 1000 ("Power Tool Dragon": 2000 → 3000/2200). "Power Tool Dragon" attacks "Zeman the Ape King". After damage calculation, Leo sends "Double Tool C&D" to the Graveyard to prevent "Power Tool Dragon" from being destroyed ("Power Tool Dragon": 3000 → 2000/2200), so only "Zeman" is destroyed.

"Zeman" is also destroyed in the Duel Spirit World by having his Minus curse staff collide with Luna's courtesy of Regulus, however, he transfers the power of the Minus Curse to Devack before he is destroyed. As the dust settles, Luna sees the tablets still containg Duel Spirits, but Tobias has returned to his true form "Dark Sage".

Devack activates his face-down "Dark Matter" to draw two cards ("Magician Ape" and "Fighter Ape") and set them in his Monster Card Zones. Leo equips "Power Tool Dragon" with "Power Converter".

Turn 10: Devack

Devack draws "Earthbound Immortal Cusillu". He then Tributes his set "Magician Ape" and "Fighter Ape" in order to Tribute Summon "Earthbound Immortal Cusillu" (2800 → 3600/2400) in Attack Position.

Leo is scared since he does not have a Mark of the Dragon and is therefore going to be absored into Cusillu, but Devack says that Cusillu's power comes from a different source, the Duel Spirit World.

In the Duel Spirit World, the captured spirits are being absorbed into the heart of Cusillu. Dark Sage and Regulus send Luna back to the Real World to finish what Leo started.

"Cusillu" attacks directly via its own effect, but Leo activates the effect of "Power Converter" to send it to the Graveyard and increase his Life Points by the ATK of "Power Tool Dragon" as well as reduce the ATK of "Power Tool Dragon" to 0 ("Power Tool Dragon": 2000 → 0/2200) (Leo 2000 → 4000). The direct attack continues (Leo 4000 → 400).

Luna, at this point, takes over for Leo. Devack then activates his face-down "Cursed Prison" to Special Summon "Ancient Fairy Dragon" from his Extra Deck (2100/3000) in Defense Position. On Devack's End Phase, the effect of "Power Converter" expires ("Power Tool Dragon": 0 → 2000/2200).

Turn 11: Luna

Luna draws "Limiter Removal". Luna's hand currently contains "Urgent Tuning", "Pot of Avarice", "Gadget Hauler", "Respect Synchron", and "Limiter Removal". Luna activates the first effect of "Power Tool Dragon" to add a random Equip Spell Card from her Deck to her hand ("Central Shield"). Luna then equips "Central Shield" to "Power Tool Dragon". Now if any other monster besides "Power Tool Dragon" is attacked, Luna will take no Battle Damage. Also, "Central Shield" forbids Devack from attacking directly. Luna Sets two cards.

Turn 12: Devack

Devack draws. "Earthbound Immortal Cusillu" attacks "Power Tool Dragon", but Luna activates her face-down "Limiter Removal" to double the ATK of "Power Tool Dragon" (Power Tool Dragon: 2000 → 4000/2200). Damage is calculated (Devack 2500 → 2100), but Devack activates the effect of "Cusillu" to Tribute "Ancient Fairy Dragon" and prevent the destruction of "Cusillu" as well as halve Luna's Life Points (Luna 400 → 200).

Luna activates her face-down "Respect Synchron" to Special Summon "Ancient Fairy Dragon" (2100/3000) from Devack's Graveyard to her side of the field in Attack Position, ignoring the Summoning conditions.

This is symbolized by Regulus biting through the chains, and setting Acient Fairy Dragon free.

On Devack's End Phase, the effect of "Limiter Removal" expires (Power Tool Dragon: 4000 → 2000/2200). Luna then sends "Central Shield" to the Graveyard in order to prevent "Power Tool Dragon" from being destroyed by the last effect of "Limiter Removal".

Turn 13: Leo/Luna

Leo, at this point, rejoins Luna. They draw "Rocket Pilder". Luna activates the effect of "Ancient Fairy Dragon" to destroy "Closed Forest" ("Cusillu": 3600 → 2800/2400) and gain 1000 Life Points (Leo/Luna 200 → 1200). With no Field Spell on the field, the effects of "Cusillu" are negated. Luna then activates the first effect of "Power Tool Dragon" to add a random Equip Spell Card from her Deck to her hand ("Pain to Power").

Luna then equips "Rocket Pilder" to "Power Tool Dragon" and equips "Pain to Power" to "Ancient Fairy Dragon". Luna's hand now contains "Pot of Avarice", "Gadget Hauler", and "Urgent Tuning".

"Power Tool Dragon" attacks "Earthbound Immortal Cusillu". Damage is calculated (Leo/Luna 1200 → 400), but due to the first effect of "Rocket Pilder", "Power Tool Dragon" isn't destroyed. The second effect of "Rocket Pilder" then decreases the ATK of "Cusillu" by the ATK of "Power Tool Dragon" ("Earthbound Immortal Cusillu": 2800 → 800/2400). Due to the effect of "Pain to Power", "Ancient Fairy Dragon" gains ATK equal to the Battle Damage Leo and Luna just received (Ancient Fairy Dragon: 2100 → 2900/3000).

"Ancient Fairy Dragon" attacks "Earthbound Immortal Cusillu". The attack destroys "Cusillu" (Devack 2100 → 0), but the conclusion of the Duel is not shown until the next episode.

Leo and Luna win.

Aftermath
Leo congratulates Luna, but Devack, who starts crumbling to dust, tries to kill the twins, which Yusei prevents. After Devack's body crumbles, the captured Duel Spirits are released and the Monkey mark disappears from the sky. Luna takes her Ancient Fairy Dragon Card and activates the tower, which sinks into the earth. And with that, Trudge, the twins and Yusei head off to the Tower of Ccapac Apu.

Luna