From Yu-Gi-Oh!

A Nightmare Reborn! Machine Emperor Skiel is the seventy-eight episode of Yu-Gi-Oh! 5D's.

The person Leo and Luna had been fighting turns out to be Lucciano. Adding to the surprise, Lucciano summons "Machine Emperor Skiel".

Summary

Leo and Luna vs. Lucciano

After summoning Machine Emperor Skiel Infinity, Lucciano immediately sets his sights on Leo, attacking him directly. In response, Luna manages to summon Ancient Fairy Dragon and Fairy Archer, and uses the later's effect to directly damage Lucciano's life points. Meanwhile, having been alerted through their Marks, Yusei, Jack, Crow, and Akiza arrive on their Duel Runner, surprised to discover that there are more than one type of Infinity monsters.

On his next turn, Lucciano uses Machine Emperor Skiel Infinity's synchro capture effect to absorb Ancient Fairy Dragon and increase its own attack power. It is then that Leo manages to get a glimpse of his eyes through his helmet visor and recognizes him from the Duel Academy. Lucciano says that it doesn't matter if they've discovered his true identity, and directly attacks Leo again, but Luna manages to halve the damage with Twinkle Wall.

Leo starts his counter attack by summoning Power Tool Dragon and Morphtronic Cleanen. He uses Morphtronic Cleanen's monster effect to try to briefly remove Machine Emperor Skiel Infinity from the field, but Lucciano manages to thwart him. Leo then uses Power Break to get Ancient Fairy Dragon back from Machine Emperor Skiel Infinity and deal damage to Lucciano's life points. Furious, Lucciano powers his monster up with Skiel A5 and attacks him directly once again, bringing his life points down to 0. Leo is knocked off of the highway, but the five Signer marks react, and the Crimson Dragon manages to guide him to safety.

Now alone, Luna tries to use a combination of Regulus and Ancient Sunshine to bring Lucciano's life points to 100, but Lucciano counters with Infinity Force, which destroys her monsters and leaves her open to another direct attack. Machine Emperor Skiel Infinity finishes off her life points, and Lucciano manages to escape with the win.

Vanished Memories

In the aftermath, the group goes to where Lucciano's mansion was, but only find an empty, grassy lot. No one at Duel Academy seems to know or remember Lucciano either. Concerned with enemies like these, Yusei decides that they must figure out the secrets of Accel Synchro.

Featured Duels

... continued from last episode.

Leo sets "Morphtronic Scramble" face-down in his Spell & Trap Card Zone and ends his turn.

Lucciano activates his face-down "Trap Stun" preventing any Trap Cards being activated. He attacks Leo directly with "Machine Emperor Skiel Infinity" (Leo: 1800 Life Points), Lucciano sets 1 card face-down in his Spell & Trap Card Zone and ends his turn.

Luna summons "Sunlight Unicorn" (ATK: 1800). She activates the effect of "Spore" in her Graveyard allowing her to remove "Nettles" from her graveyard to Special Summon it (ATK: 800). "Spore's" effect makes its Level become the same of "Nettles" (LV: 3). Luna uses "Sunlight Unicorn" and "Spore" to Synchro Summon "Ancient Fairy Dragon" (ATK: 2100). She activates the effect of "Ancient Fairy Dragon" to Special Summon "Fairy Archer" (DEF: 600). She activates "Fairy Archer's" effect to inflict 400 damage for each LIGHT monsters she controls (Lucciano: 3200 Life Points). Luna then places 2 cards face-down in her Spell & Trap Card Zone and ends her turn.

Lucciano activates the effect of "Machine Emperor Skiel Infinity" and equips "Ancient Fairy Dragon" to it (ATK: 4300). He activates "Speed Spell - Summon Close" allowing him to prevent both Luna and Leo from Special Summoning any monsters for the rest of the turn. He attacks Leo directly with "Machine Emperor Skiel Infinity" but Luna activates "Twinkle Wall" allowing her to negate the attack, by taking the damage to herself by half of its that monster's ATK instead (Luna: 350 Life Points). Lucciano places 1 card face-down in his Spell & Trap Card Zone and ends his turn.

Leo summons "Morphtronic Scopen" (ATK: 800). He activates "Morphtronic Scopen's" effect and special summon "Morphtronic Boomboxen" (ATK: 1200). He uses "Morphtronic Scopen" and Morphtronic Boomboxen" to Synchro Summon "Power Tool Dragon" (ATK: 2300). He activates "Speed Spell - Summon Speeder" to special summon "Morphtronic Cleanen" (DEF: 0). He activates its effect equipping "Machine Emperor Skiel Infinity", but Lucciano activates "Ghost Convert" negating the effect of "Morphtronic Cleanen" and forcing "Morphtronic Cleanen" to absorb a monster in Lucciano's Graveyard. Leo places 1 card face-down in his Spell & Trap Card Zone and ends his turn.

Lucciano draws. Leo activates "Power Break" allowing him to return all Equip Spell Cards to their owners' Decks and inflict 500 points of damage to Lucciano for each card returned since he has "Power Tool Dragon" on his field (Lucciano: 2200 Life Points). Lucciano activates the effect of "Speed World 2" and draws 1 card from his deck. He activates "Sky A3" letting Lucciano send "Skiel Attack" to the Graveyard and special summon "Skiel Attack 3" (ATK: 1200). He activates "Skiel Attack 3's" effect to Tribute it and special summon "Skiel Attack 5" (ATK: 1600). Lucciano activates the effect of "Skiel Attack 5" allowing "Machine Emperor Skiel Infinity" to attack Leo directly (Leo: 0 Life Points). Lucciano sets 1 card face-down in his Spell & Trap Card Zone and ends his turn.

Luna summons "Regulus" (ATK: 1700) she then activates "Ancient Sunshine" to remove "Ancient Fairy Dragon" from the game to inflict damage to its ATK since she has "Regulus" on her field. Lucciano chains with "Infinity Force", negating the damage and destroying all monsters on Luna's field.

Lucciano declares a direct attack with "Machine Emperor Skiel Infinity" (Luna: 0 Life Points).

Lucciano wins.

Card creation contest

At the end of the credits, it was shown that "Morphtronic Cleanen" was chosen to become a card in the anime as a result of a drawing competition.