Juggernaut Drive

Juggernaut Drive, also known as the Dragon of Supremacy, is a special ability of the Longinus - Boosted Gear and Divine Dividing.

Summary
A special ability of the Longinus - Boosted Gear and Divine Dividing, and are considered to be forbidden moves. The Juggernaut Drive temporarily removes the seal placed on the Heavenly Dragons, but the users will lose their sanity while their lives are devoured by the power.

Juggernaut Drive contains a curse made up of the negative emotions of the past possessors of the Boosted Gear and Divine Dividing that influences the current user to enter this form. The curse of the Juggernaut Drive can be permanently removed if the hatred of its past possessors are dispersed.

For other Sacred Gears that have creatures sealed inside (such as the Regulus Nemea), their Juggernaut Drive goes under a different name called "Breakdown the Beast", also known as the Beast of Supremacy, but functions the same way.

Chants
A special chant must be used to activate Juggernaut Drive.

The chant for the Boosted Gear's Juggernaut Drive goes as follows:

English=
 * I, who is about to awaken,
 * Am the Heavenly Dragon who has stolen the principles of domination from God
 * I laugh at the "infinite", and I grieve at the "dream"
 * I shall become the Red Dragon of Domination
 * And I shall sink you to the depths of the crimson purgatory!

Kana=
 * 我、目覚めるは
 * 覇の理を神より奪いし二天龍なり
 * 無限を嗤い、夢幻を憂う
 * 我、赤き龍の覇王と成りて
 * 汝を紅蓮の煉獄に沈めよう

Romaji=
 * Ware, mezameru wa
 * Ha no ri o kami yori ubaishi Nitenryū nari
 * Mugen o warai, mugen o ureu ga
 * Akaki ryū no haō to narite
 * Nanji o guren no rengoku ni shizumeyou

The chant for Divine Dividing's Juggernaut Drive goes as follows:

English=
 * I, who is about to awaken,
 * Am the Heavenly Dragon who has taken the principles of supremacy from God
 * I envy the "infinite" and I pursue the "dream"
 * I shall become the White Dragon of Supremacy
 * And I shall take you to the limits of white paradise

Kana=
 * 我、目覚めるは
 * 覇の理に全てを奪われし二天龍なり
 * 無限を妬み、夢幻を想う
 * 我、白き龍の覇道を極め
 * 汝を無垢の極限へと誘おう

Romaji=
 * Ware, mezameru wa
 * Ha no ri o kami yori ubaishi Nitenryū nari
 * Mugen o netami, mugen o omou ga
 * Ga, shiroki ryū no hadō o kiwame
 * Nanji o muku no kyokugen e to izanaou

Plot
In Volume 6, Issei unintentionally activates an incomplete form of Juggernaut Drive due to the overwhelming negative feelings that appear after Asia's apparent "death" at the hands of Shalba Beelzabub. Issei went berserk and ripped Shalba's arms off, Shalba found himself overpowered and incapable of defeating Issei, but manages to escape at the last second. The Oppai Dragon's theme song was played to calm Issei enough for Vali to reduce Issei's power. Issei exited Juggernaut Drive by poking Rias's breasts.

In Volume 7, Vali activated the Juggernaut Drive during the battle against Loki, however, unlike Issei, he was able to temporarily negate the Juggernaut Drive's negative effects by using his demonic power as a source of power instead of his life-force. He was then teleported by Kuroka to fight against Fenrir elsewhere.

In Volume 10, during his fight with Sairaorg, Issei nearly went Juggernaut Drive again under the negative influence from the past possessors but manage to resist it and change their view points, this in turn gave issei a new form Cardinal Crimson Promotion.

Abilities
The Juggernaut Drive unleashes the full power of the Two Heavenly Dragons sealed in both the Boosted Gear and Divine Dividing, granting the user power that is said to rival God's. The immense power is so great that upon activation, its aura would have destroyed the urban areas and their surroundings.

While in this form, the user has a greatly increased flight speed to the point where it can be hard to follow with ones eye sight, this form is also capable of fending off powerful attacks by simply flapping it wings. From the various jewels all over the armor can grow multiple Dragon arms and blades. It can fire laser beams from a small cannon within the mouth of the helm.

While in Boosted Gear's Juggernaut Drive, Issei somehow froze Shalba Beelzebub with an ability similar to Forbidden Balor View, this was later revealed to be Gasper Balor's doing, as he was allowing Issei to use his "eyes".

Issei's most powerful attack is the Longinus Smasher, previously only available in the Juggernaut Drive. An energy beam of immense destructive power fired from a launcher hidden in the chest.

Drawbacks
The Juggernaut Drive is a double edged sword despite its overall power. In this mode, the possessor will obtain immense power, but at the cost of the user's life and sanity, in which the possessor will continuously destroy everything around them and even themselves, until they die.

Forms
Juggernaut Drive appears very similar to the Scale Mail, however it takes a much more Dragon-like appearance, possessing claw-like growths on the hands and feet, as well as horns and a fanged mouth on the helmet, the mouth being capable of delivering deadly bites to opponents.

Trivia

 * Juggernaut Drive was originally stated to be a special ability which was exclusive for Sacred Gears with powerful creatures inside. Though in Volume 11, it was changed to a special ability exclusive for Sacred Gears with the Heavenly Dragons residing in them (Boosted Gear and Divine Dividing). For other Sacred Gears with other creatures residing in them, a new name, called Breakdown the Beast, was given.
 * The "infinity" and the "dream" used in the chants are references to the Dragon God Ophis and the True Dragon, Great Red. Ophis represents the "infinite", as she was born from the "nothingness" of infinity, while Great Red represents the "dream", as he was born from the "illusions" of dreams.
 * Longinus Smasher appears to be a homage to the Mega Smasher from the Guyver series.
 * In the english dub, Vali shortens the name to just "Juggernaut".