He was voiced by Ryôta Takeuchi in the Japanese version, and Liam O'Brien in the English dubbed version.
Isaac is a tall man with an unusually long ahoge. In the past, he didn't wear much armor and he had a more relaxed features. He was usually smiling and had big eyes. In Dunya's creation, he wears armor and usually seems to have a bored look.
Isaac cares for Dunya very much and even sacrificed his life in order to save the princess.
Isaac was Dunya's servant at the Musta'sim Kingdom. He took care of the Dunya until she announced that Isaac must serve the whole kingdom and not her alone for she will be married to a duke due to financial reasons.
At the war of the scholars and the nobles, Isaac with Dunya, tried to escape the Kingdom in order to save the 13 year old princess. All of the nobles were killed, and the scholars and palace guards wanted all of the Royal Family's heads to be presented to the crowd, so they had to kill the princess. Isaac tried to explain the situation for the little princess has not sinned and wasn't not aware of the situation, but while he tried to to do it, he was killed by the guards saying that everything was done by Fate.
Isaac arrives, together with Dunya Musta'sim and Ithnan, in the Toran Village where the Dungeon Zagan is located. They present themselves as merchants from Reim Empire and asked the people for baptism. They say that their goal is to buy Toran crafts.
While the Fake Zagan is telling Aladdin, Alibaba, Hakuryuu and Morgiana about the real Zagan in the treasury room, Dunya attacks the little creature causing it to die instantly. While Dunya fights Aladdin, Isaac confronts Alibaba. First, he easily overpowers Alibaba, but when he changes the huge Amon's sword to the Amon's Royal Sword, Alibaba reaches to hurt him. Isaac is chopped plenty of times, although he doesn't seem to die and rises all the time. After Dunya changes to Dark Djinn Equip, he activates his Household Vessel, Al Kaus Kauza, that allows him to move to an incredible speed due to magnetism. When Dunya activates her Extreme Magic, Rea Baldo, Isaac blocks Alibaba and Hakuryuu's attacks, not falling for any attack. After Dunya's magic fails he tries to protect her, but since she run out of Magoi and her Gravity Magic was the only thing that maintained him up, he falls.
Dunya collapses and starts to cry, so Aladdin uses Wisdom of Solomon to find Isaac's Rukh and they meet for a last time. Isaac's final words are: "Please find happiness" and embraces the princess. He then vanishes.
Powers and Abilities
- Skilled Swordsman - He is shown to be skilled in swordplay possessing similiar level of skill to that of Sharrkan. When combined with his Dark Household Vessel his swordplay becomes unpredictable.
The Dark Djinn that Isaac drew his power from was Dunya Musta'sim.
Dark Household Vessel
- Al Kaus Kauza (Black Magnet Armor) - It gains its power from the Dark Djinn, Dunya Musta'sim. Al Kaus Kauza repels the strong magnetic forces between the Earth's surface and its armor. This results in superhuman acceleration.
- Isaac bears a resemblance to Sōsuke Aizen, the main antagonist of the anime and manga, Bleach.