Demon King of the Sixth Heaven/Alternative

Demon King of the Sixth Heaven is an special magical technique created by Ichijou Tsukino from the DxD: Twice Critical version, which combines both a high form of thaumaturgy and the secondary abilities of his Sacred Gear, Memento Iron Maiden in order to create something akin to an one-man army, also earning him the title as a Hellion(悪たれ; akutake).

A powerful offensive ability, due to the sheer number of shades and stamina used in order to accomplish it, it is Ichijou's least favorite spell and his Last Resort.

Summary
Ichijou's Last Resort, a powerful anti-army skill that allows him to target and fire against a total of 3,000 per usage with massive firepower damage. Although Berolina calls it a Trump Card, Ichijou generally has a dislike for it due to the sheer number of shades he has to summon and the amount of magic he has to spend on a single summon.

Such technique would make its debut during the Gion Temple Arc, in which Ichijou would summon the 3,000 matchlocks in order to intimidate the Zodiacs, but was unable to fire against Muten Okami for him being a monk, instead retreating in order to avoid fighting the monk.

Abilities
An extremely powerful ability which combines both Memento Iron Maiden's skill to store shades inside Ichijou with a highest form of Thaumaturgy, Demon Lord of the Sixth Heaven takes the shades of those who died a violent death and whose regrets revolves around not being able to protect their loved ones or territory, their hubris, rage and resentment consuming the remaining humanity the shade once had until it becomes a sphere of concentrated negative feelings and nothing else. By summoning such shades with his Sacred Gear, Ichijou is able to tranfigure them into a more physical form in the shape of a bullet using magic, which them forms a matchlock gun around itself that fires under his command, the sheer power of said bullet being able to destroy its original container and cause damage compared to a Big Game rifle, Ichijou saying that those are the manifestations of all the negatives feelings said shade had inside himself.

However, while the damage it can deal is relatively minimal for an Youkai or a Middle-class devil as an unity, the true Threat present itself by the sheer number of weapons ichijou can summon at once, a total of 3,000 guns with a single shade bullet each, enough to level a Temple as big as the Gion one and when concentrated on a single target, seriously Injure the likes of a High-class devil, its power being enough to pulverize a small army of Youkai.

Since the shades are forever consumed by their own resentment and regrets they had in life, they are unable to pass one even as bullets, meaning Ichijou can store them back inside Memento Iron Maiden for later use.

Drawbacks
The sheer number of muskets and souls used in order to bring forth such devastating spell is considered enormous, and as such Ichijou considers it a Last Resort since after a single use he claims he has no more energy to fight or use any other kind of magic, meaning he has to rely on Berolina or any other possible ally he has to carry him out of conflict.

Also, Demon Lord of the Sixth Heaven has no power set, meaning Ichijou cannot control the destruction he causes and, even used dispersedly on a larger area, the amount of damage and sound it causes will attract unwanted attention. The bullets, being shades themselves, can be recovered and exorcized once they no longer possess a threat, making Ichijou lose a few shades once every use for either losing it or them being exorcizes away before he can store them back.

Formations
Formations(形成; Keisei), are names given to variations of how and when Ichijou fires Demon Lord of the Sixth Heaven, being on a single target of having an anti-army variation, both having an enormous amount of firepower enough to cause a small earthquake.
 * Hiei(飛影; Lit. Flying Shadow) - 
 * An anti-unity variation, Ichijou instead creates a dome out of the musket and aims them on a single or a small group of targets, forming three rows of a thousand weapons each that overlap each other. On Ichijou's command, the three rows of muskets fire according to the proximity they have from the target, the first row of thousand to destroy any form of protection from the targets and weaken them, the second to kill them, and the third to make sure they were completely annihilated, each row having the combined power of a meteoryte and being able to leave a massive crater on the Earth.


 * An anti-army variation, Ichijou points all of his muskets forward and fire them at once, all bullets having the strength of a big-game Gun and being enough to completely override an entire youkai army and create a massive fire and collateral damage, the sound produced by the 3,000 muskets firing and exploding also being loud enough to create a powerfuk shockwave and blow small personell away.
 * Three Thousand Worlds(三千世界; Sanzensekai) - An anti-army variation, Ichijou points all of his muskets forward and fire them at once, all bullets having the strength of a big-game Gun and being enough to completely override an entire youkai army and create a massive fire and collateral damage, the sound produced by the 3,000 muskets firing and exploding also being loud enough to create a powerfuk shockwave and blow small personell away.


 * Three Thousand Worlds(三千世界; Sanzensekai) An anti-unity variation, Ichijou instead creates a dome out of the musket and aims them on a single or a small group of targets, forming three rows of a thousand weapons each that overlap each other. On Ichijou's command, the three rows of muskets fire according to the proximity they have from the target, the first row of thousand to destroy any form of protection from the targets and weaken them, the second to kill them, and the third to make sure they were completely annihilated, each row having the combined power of a meteoryte and being able to leave a massive crater on the Earth.ia

Trivia

 * Image and appearance based on the Three Thousand Worlds from the fate/ Series.
 * Unlike its DxD: R counterpart, this Demon Lord of the Sixth Heaven is actually a reference to Nobunaga Oda, a powerful feudal lord of the 16th century and regarded as one of the three unifiers of Japan, being also known for most brutal suppression of determined opponents and modernization of their military tactics, being a self-proclaimed Demon Lord of the Sixth realm.
 * Although the ideograms used were different, Hiei is named after the Siege of Mt. Hiei, a military campaign in which Nobunaga surrounded and burnt down the eponymous Mountain and killed all the people, including women and children, with his army.
 * Three Thousand Worlds is named after