|Guardia de Mieux|
|Debut||Ninja Gaiden (NES)|
A bizarre sorcerer with purple skin dressed in a red torn tunic with a Hexagram embroidered on the front and a purple skeleton of a demon wrapped in his body like an armor.
A bunch of eyes are attached around his body. In the TurbografX-16 / PC Engine have tormentous faces with a suffering expressions around the helmet.
Ninja Gaiden (NES) Edit
After Walter Smith, a professor and acquaintance of Jô Hayabusa seals off an ancient ruin in South America, Guardia de Mieux, the Jaquio appears and takes control of the ruin. Jaquio awaits Ryu Hayabusa after he sends his assassins, the Malice Four to steal the Demon Statue break the seal on the Dark God, plunging the world into darkness. After the MaliceFour steal the Shadow Statue from Ryu's father, Joe Hayabusa, Jaquio tricks Ryu into surrendering the Light statue while he prepares the ritual in front of the Demon's body in an Amazon temple. He succeeds in breaking the seal on the Demon but is defeated by Ryu and the Dragon Sword.
Ninja Gaiden II: Dark Sword of ChaosEdit
Jaquio is initially mentioned by Ashtar, who was apparently the Jaquio's boss all along through the events of the first game.
After Ashtar is defeated by the Dragon Ninja Ryu, Jaquio reveals himself somehow fully resurrected. He takes Irene hostage and grievously wounds the US Army agent, Robert T. Sturgeon. He soon meets Ryu in a demonic altar, and reveals that the energy of the spirit of the Demon flowed into his body after their last battle, resurrecting him, and giving him unfathomable evil power.
Despite his powers he is beaten by Ryu. However, his blood flowing out touches the cursed blade of the Sword of Chaos, and it sucks the life out of Irene. The gates of Hell are thrown open and the revived Jaquio takes on the form of a demon. He challenges Ryu, and is once again defeated by the Dragon Ninja. After his defeat, the Sword of Chaos is destroyed and the Hell Gate is sealed, as the castle collapses.
- In the PC and the TurbografX-16 versions he's called the "Devildoer" in English
- Jaquio's name is mentioned in the OAV by Robert spelled Jakyo.
- In the OAV a flashback shows Jaquio with the "Dark Sword of Chaos" on his hands.