Gunpla is the Greatest!

Gunpla is the Greatest! is the fifth and final episode of Gundam Build Fighters: Battlogue.

Synopsis
One day, Tatsuya Yuuki visits Iori Models, where Sei Iori's family lives. Next week, Tatsuya will begin a tour of Europe as Meijin Kawaguchi. But he has heard from Mao Yasaka that Sei has modified his Build Strike Cosmos into the Build Strike Galaxy Cosmos, and before he leaves, Tatsuya wants to play Gunpla Battle against Sei's new machine. Sei eagerly accepts this proposal, and begins a one-on-one match against the new Gunpla that Tatsuya has built for his overseas tour.

Plot
At Iori Models, Rinko is busy dusting off the various models in the story as Sei is putting the finishing touches on a shield when someone enters the store - Tatsuya, not dressed up as the Meijin. Sei is surprised as Tatsuya explains he's going on a tour in Europe as the Meijin, and though he doesn't say it outright, he wants a match with Sei, which he agrees to. With Rinko giving the two privacy in the Gunpla Battle room, Tatsuya reveals that Mao Yasaka told him he modified the Build Strike Cosmos. Sei confirms and reveals the Build Strike Galaxy Cosmos. Tatsuya's impressed with the work, musing he must have even improved the RG System. Sei wonders if Tatsuya's going to use the Ballistic Zaku for his tour, which Tatsuya denies, revealing the A-Z Gundam. Sei is impressed - it's designed for maximum maneuverability and firepower and coated in Yajima Trading's new counter-particle paint. Sei is fired up - he wants to fight the A-Z Gundam and Tatsuya wants to fight the Galaxy Cosmos, but not as the Meijin, but as Tatsuya. With everything set, the two prepare for battle, launching their Gunpla into space.

After connecting with the Galaxy Cosmos' flightpack, Sei is taken off guard as Tatsuya races in in Waverider mode, slips past him, then returns to MS Form to use his suit's beam cannon to completely obliterate Luna II. Sei realizes Tatsuya did that to give him a chance to see his Gunpla's capabilities. Tatsuya confirms this and begins the battle for real, turning his Gunpla's weapon on the Galaxy Cosmos, who blocks it by using the Star System to create a beam shield. Sei fights back, but the A-Z proves to be much faster, which Sei surmises to be at least six times faster, such is the skill of the Crimson Comet. Tatsuya knows what's next as Sei activates RG and Star System at the same time, meeting the A-Z in a clash of beam sabers. Breaking away, the two continue to clash, their vulcan cannons not even piercing their shells, leading to Tatsuya to use the A-Z's Prime Cannons. Sei blocks the attack, but the sheer power launches the Galaxy Cosmos into the Earth's Gravity Well.

However, Tatsuya rescues Sei, but only because he wants to finish the match his way. As they continue their descent, Sei goes for his beam rifle, but Tatsuya shoots it out of his hand. Sei kicks it, causing Tatsuya to be blinded briefly as he destroys it. This allows Sei to race in and stab the A-Z's cannon with a beam saber, destroying it. This doesn't stop Tatsuya, who creates a beam blade that clashes with Sei's and destroys it and the Galaxy Cosmos' arm. He transforms, grabs the Galaxy Cosmos and prepares to piledriver the Gunpla into the nearby island. At the last moment, Sei is able to boost the two of them away into the ocean.

The two suits emerge, but the Galaxy Cosmos is in terrible state. However, Sei decides to keep going, one last fight, because that's what Reiji would have done. The two go in for one last beam saber slash, but in a major fluke, the Galaxy Cosmos' knee gives out, allowing Sei to dodge Tatsuya's strike and damage the A-Z in the waist. The two fall, unmoving. It's a tie. As the battle ends, Tatsuya is impressed, but Sei is displeased - to him, a draw is just as bad as a loss and that the dodge was just luck. Tatsuya tells him that's how battles are and wants a rematch when he returns from Japan. Sei agrees and shakes his hand. However, he wonders if it was a good idea to wreck the A-Z so soon. Tatsuya says "no", but decides to take the time to fix it up here and now. Sei realizes that he fought him to make the A-Z better, "rebirth from destruction", causing Tatsuya to wonder if he was trying to be witty.

Characters

 * Sei Iori
 * Tatsuya Yuuki
 * Rinko Iori

Mechanic

 * Build Strike Galaxy Cosmos
 * A-Z Gundam

Trivia

 * This episode marks the final episode of the Battlogue series.
 * Tatsuya using the A-Z to rescue the Galaxy Cosmos mimics other incidents in Gundam meta such as the MSZ-006 Zeta Gundam rescuing the AMX-004 Qubeley Mk-II, the Archangel rescuing the GAT-X105+AQM/E-X01 Aile Strike Gundam and others.
 * The island where Sei and Tatsuya crash on is Cucuruz Doan's Island.
 * The episode ends with a message revealing a new Build Fighters story February 2, 2018.