According the Prayer of Necromantale, a sect of fiends that deify and worship Vazdah, he was born from the body of Vigoor, ancestor of all fiends, in an age of myth and legend. Until the time of fiend rule over man came about, he laid dormant and was awakened by the battles of the Greater Fiends and their great armies for dominance over regions of the planet and the humans. As Vazdah awoke, he looked upon Dagra Dai, a human philosopher, and his evil stare was able to drive the human mad and fill him with great evil power. Dagra Dai became the Infernal High Priest and Vazdah proceeded to the conflicts that had roused him, forcing the Greater Fiends to unify under his rulership. It was in these ancient times that he battled the other Supreme Evil Deities for control of all the fiends and humans with Vigoor emerging the victor, becoming unquestioned ruler. Also during this time, Ryu Hayabusa's ancestors, the Dragon Lineage, swore to defeat the fiends and Vazdah and his servants were defeated by one of them. The Greater Fiends were scattered across the Earth and sealed into eternal slumber while the Archfiend was destroyed, his essence sealed in a portal within Mt. Fuji. Only with a demonic statuette would Vazdah and his Greater Fiends be free again.
Ninja Gaiden II
Millennia later, the destruction of Vigoor and his sect by Ryu Hayabusa left a void of power amongst the fiends, one that Vazdah and his followers would fill. Dagra Dai succeeded in freeing Elizébet, one of the Greater Fiends, and gave her the job of freeing the rest since only when the hearts of the Greater Fiends enchanted the demon statue could it open the monolith gates keeping Vazdah in the Underworld. When the demonic statue was stolen from the Castle of the Dragon, Ryu set out across the world to get it back as he followed Elizébet's trail, taking on the other Greater Fiends that she released, energizing the statue. She brought it back to Dagra Dai and with its use, Mt. Fuji exploded as a gateway to the Underworld opened, created by Earth and the realm of the fiends fusing together.
The Infernal High Priest entered the Underworld where he performed a blood ritual that released Vazdah in his larval form and as the ritual would go on, he would shed this form to enter his previous greatness. With some time on his side, Ryu descended into the Underworld, fighting his way through hordes of fiends and the Greater Friends he had slain back on Earth. He managed to enter the monolith gates with the hearts he had gotten from the Greater Fiends and went on, finally coming across Dagra Dai in the middle of the ritual, meaning Vazdah was still in his larva statue. The Infernal High Priest attacked Ryu and was defeated, leading to him desperately sacrificing himself to use his own flesh and blood to give the Archfiend power, but it was not enough to complete the ritual. Vazdah attempted to climb his way out of Mt. Fuji in his incomplete larval form but Ryu pursued him. Seeing the ninja as nothing but a pest, the Archfiend unleashed everything he had on him, however Ryu managed to strike Vazdah's weak points. The dying Archfiend fell to the bottom of the volcano shaft and with his death, the portal began disintegrating and the ties between the Underworld and Earth severed. But during the battle, Ryu's arm was injured and a drop of blood fell from it, landing on Vazdah's body and completing the blood sacrifice. The Archfiend shed his larval carapace and rocketed up the volcano shaft towards the surface with Ryu leaping after him. On Mt. Fuji's surface the Dragon Ninja, armed with the True Dragon Sword and Genshin's Blade of the Archfiend, and the Supreme Archfiend faced off. Vazdah unleashed hell upon Ryu with all his demonic power and the ninja fought back with all his skills. As the battle began to reach its conclusion, the Archfiend began to weaken and lower his guard with the Dragon Ninja taking advantage of this to finish him off. Ryu executed a series of lightning fast obliteration attacks, finishing with a final strike to Vazdahs head. The Archfiend exploded, emitting large amounts of energy and severing the connection between the underworld and the Earth completely.
- Agility: Slow and sluggish in his first form, he is fast and agile in his true form and able to teleport and move at lightning fast speeds.
- Strength: Vazdah's strength is at an immense level, almost limitless.
- Durability: Vazdah's durability is at an immense level, nearly limitless.
- Power: In his true form Vazdah has virtually unlimited power, able to affect the world on a universal scale.
- Conversion: Being an Archfiend Vazdah could turn beings into fiends by merely looking at them, much like he did to Dagra Dai.
- Ghost Skull: Vazdah will summon blue flaming Ghost Skulls to follow and home in onto his enemy.
- Melee: His main melee attacks are arm slam, arm swipe and a tail swipe.
- Demon Beam: A high damage attack, a large energy beam will blast out of his mouth. Usually when he is weakened.
- Blood Vomit: Throughout the battle Vazdah will vomit up blood and guts, usually right after he is damaged.
- Flight: Unlike his first form, in his true form he is able to agilely fly through the air. Since he doesn't flap his wings it's assume to be psionic powered flight.
- Melee: These are generally arm attacks and grabbing attacks.
- Ground Slam: While flying, Vazdah will fly full speed, slamming into his enemy on the ground.
- Teleport: An evasive move where Vazdah blinks from one place to another in a mist of darkness.
- Hell Fire: Vazdah summons meteorites from deep within the volcano to rain down on his enemies.
- Lightning Bolts: Vazdah creates electric bolts that temporary electrifies a section of the ground.
- Demon Beam: A large beam of energy blasted from his forehead, dealing massive damage, Vazdah is also able to sweep around for his targets with this attack.
Vazdah is the embodiment of all things that are immoral and is quite power hungry, willing to selfishly and ruthlessly sacrifice his servants as a means of furthering his own power. This is best demonstrated by the Gaja, a race of female fiends, who were once beautiful mermaid like creatures before they gave into Vazdah's indulgences with his corruption turning them into their terrible fiend forms. Also, though the Archfiend's revival would mean doom and destruction for most of the human race, he does not desire to destroy all life, instead seeking to be unquestioned ruler of all and to kill any who do not submit to him.
- In his larval form, Vazdah has one eye that hangs loose and his true form resembles the Devil.
- During the battle with his larval form, the player has to defeat him in a certain amount of time, the time it takes him to crawl out of the volcano.
- Vazdah is somehow related to Vigoor.
- Vazdah's True Form resembles Devil, Deity of Immorality.