Zagan appears before Aladdin, Alibaba, Morgiana and Hakuryuu asking who will become a king. He then introduces himself as a Djinn of loyalty and purity. He bows deeply before Aladdin and apologizes. He promises to undo the Magic cast on the Torran villagers and asks for forgiveness for not being able to do anything before. He gives Morgiana part of his Magoi to save her life. However, when Alibaba tries talking to him, he vomits on him and asks to let only Magi talk to him, because not-Magi make him sick, as he really hates humans.
He decides to finally choose the king. His choice is Hakuryuu, who doesn't really agree with this. Zagan explains that he's the most talented when it comes to using him and has the most Magoi of the gathered eligible to obtain him. Also, his Magoi Manipulation is compatible with his abilities. Hakuryuu still thinks that there are people more suitable than him. Zagan realizes that he's talking about Alibaba but thinks that he is totally out. He says that he wouldn't work under the same master as Amon, and above all, Alibaba wasn't even able to master Amon. He adds that he doesn't want to become the second choice for someone who can't even handle a single Djinn.
Zagan notices that Hakuryuu still can't accept this and asks him why does he look like he's reached the end after merely getting a Djinn. He tells him that what makes somebody the king is what he'll do after obtaining the power and what kind of king he will become depends on him. He then hides himself in Hakuryuu's Metal Vessel.
Hakuryuu Ren is Zagan's Dungeon Capturer. As a Djinn, he can alter his size and rule his Dungeon. However, unlike other Djinns he gave the role of ruling the Dungeon to Fake Zagan. Zagan has the ability to create and control life, animals and plants. Zagan's Metal Vessel is a spear. Hakuryuu's Household is made up of creatures that he made into his servants with Zagan’s power.
- Djinn Weapon Equip: After compressing Zagan's powers around his spear, he summons a two-sided spear with a pointed tip on each.
- Zaug Mobarezo (Dragon-Taming Wooden Lotus Shock): This attack originates from his artificial arm, it releases several wooden projectile dragons able to bite an opponent.
- Zaug Al-Adhra (Manipulated Life Bow): He can also fire his monsters off by holding his spear like a bow and arrow, firing off multiple monsters at once.
- Djinn Equip: Hakuryuu is able to perform a half body Djinn Equip complete with his weapon. In this form, he is able to equip exactly half of his body, with the right side being normal and the left side being that of his Djinn. Once he has equipped half of his body with Zagan's power, he can become a being more close to a Djinn and his abilities are not limited only to controlling plants his metal vessel has touched anymore. The Djinn of life Zagan, not only controls plants, but also several other creatures he can also send his Magoi to like the microscopic fungus that exists in the atmosphere make them grow, turning them into his servants. These monsters are very similar to the ones in the Dungeon, Zagan. These monsters come out every time he swings his weapon. These monsters are very acidic and can easily melt Aladdin's Borg. After six months has passed he is now capable of doing a full body Djinn Equip.
He chose Hakuryuu as his Dungeon Capturer, but seems rather fond of teasing him and making him cry. However, even though all his jokes, he says that he believes in him. He also worries about Hakuryuu as he looks at his Rukh and notices some black ones among the white.
When Amon appeared in Zagan's dungeon, he showed an immediate and unknown dislike towards him. Even before they were Djinn, he didn't seem to like Amon. As explained by Barbatos and Valefor, Zagan hated Amon since the time when they used to be master and disciple in Resistance.
- His name is probably taken from the book The Lesser Key of Solomon. In the first section of this book, entitled Ars Goetia, several demons are described, Zagan being the sixty-first. The dungeon where Zagan resided in was the 61st as well.