Diamond Weapon is a colossal magitek monster created by Verstael Besithia in the Final Fantasy XV Universe. It appears in Kingsglaive: Final Fantasy XV movie, and is mentioned in Final Fantasy XV: Episode Prompto. It also plays a major role in Aranea Highwind's chapter in Final Fantasy XV -The Dawn of the Future-.
Finally, my daemon-infused magitek armor is complete. I have christened my creation 'Diamond Weapon.' It has exhibited an extremely unstable psyche, immediately unleashing unmitigated horrors upon activation. Its destructive capabilities, however, are indeed beyond compare. Not even the 'impenetrable' Insomnia could withstand its onslaught. Why, the Crown City would fall in a mere matter of minutes.Research log: Year 756, Day 98 in Episode Prompto
In his correspondence with the emperor, Verstael refers to the Diamond Weapon as a "daemon armor", implying it is created similar to how magitek troopers are made, by powering a magitek core with miasma (the black mist emitted by lifeforms parasitized by the Starscourge). Diamond Weapon is a monstrous creature that towers over buildings. It has a glowing red sphere in its chest, and another such orb on its forehead. These might be the magitek cores that power it. Its shoulder appendages open up and shoot salvos of energy beams, demolishing everything in its path. It moves bipedally and has an appendage on its back that resembles a cape.
On 8th of April M.E. 756 Verstael informed Emperor Aldercapt that the Diamond Weapon was ready and asked him to come view the new weapon at the First Magitek Production Facility. It is possible that it was created by Verstael intentionally daemonifying the researchers working at the production facility, as the final cohesive message left behind by a team member, dated 12th of February, is: We are all... Together, we...Insomnia. As the ultimate...we... Thank you... Farewell...
Diamond Weapon is deployed to terrorize Lucis at the behest of Niflheim. When the Kingsglaive engage the empire in Duscae region, the sun sets and the empire deploys a Diamond Weapon upon them, but retreats after demonstrating its superiority to the Lucian forces. During the invasion of Insomnia, Niflheim deploys multiple Diamond Weapons against the Old Wall statues.
When the sun rises on the devastated Insomnia, the Diamond Weapons are gone. Whether Diamond Weapon can only be deployed at night is ambiguous, as even though the magitek armor is said to be lightproof, Diamond Weapon is only seen deployed at night in the movie.
As told in Final Fantasy XV -The Dawn of the Future-, Aranea finds the imperial capital of Gralea under attack by Diamond Weapon when she returns to the city from her work in Altissia. The weapon fires at her airship, and is winning against the imperial army. It heads to the Zegnautus Keep and Aranea follows alone while her subordinates save the citizens. From the roof of the Keep Aranea observes the Weapon being transported toward Tenebrae, with Chancellor Izunia gloating that is the next place he is going to destroy. Realizing that Izunia had set the Diamond Weapon loose in Gralea on purpose, Aranea tries to attack him, but he easily deflects her. Aranea declares she is quitting as commodore and makes it her mission to protect Tenebrae. After her Airborne Unit downs the transport ship carrying the Diamond Weapon, Aranea destroys the monstrosity by taking out its magitek cores one by one.
The theme "Diamond Weapon" is included on the Kingsglaive: Final Fantasy XV: Original Soundtrack as the third track.
Creation and development
The Diamond Weapon for Kingsglaive: Final Fantasy XV was sculpted by József Czakó at Digic Pictures based on concept art by Square Enix. Digic Pictures produced the battle scene where Diamond Weapon emits smoke (or possibly, miasma). In the final battle scene (made by Image Engine), Diamond Weapon appears without the smoke, and the artists working on that scene further improved the texture and surface of the model.
Final Fantasy XV -The Dawn of the Future- is a novelization of the "second season" of downloadable content that was cancelled part way and only the first part, Final Fantasy XV: Episode Ardyn, was released. Aranea's chapter implies that Diamond Weapon was to be the final boss of Episode Aranea.
- The artworks of Diamond Weapon seen on the documents in Episode Prompto are the concept art made for Kingsglaive: Final Fantasy XV.
- Lunafreya's story in Final Fantasy XV -The Dawn of the Future- features seemingly another variant of the same type of magitek armor as Diamond Weapon, the "Sapphire Weapon", which seems to have been planned as the final boss of Episode Luna. Sapphire Weapon is also a Weapon from Final Fantasy VII, albeit not named in-game.
- In Final Fantasy VII Diamond Weapon is one of the Planet's defense mechanics, deployed to destroy those who would harm its ecosystem. In Final Fantasy XV Diamond Weapon is the opposite of this, a man-made daemon construction.