Aamon's goal remains the same as it did in the original game, but steps involved are elaborated upon considerably and the scope is adjusted to accommodate the new characters added to the setting of Dragon Quest IV. He is a part of Randolfo's inner-circle and plays the role of sycophant to avoid rousing suspicion, furthering his plans in secret through the use of several agents. Aamon's chief subordinate is Furgil, a meowgician sent out to lead Psaro down the path most beneficial to him. Furgil is tasked with posing as a talent scout for a monster wrangler league and gives Psaro a piece of red-coloured travelite to grant him entry into Nadiria. Once within the demon world, Aamon spies on Psaro through out his journey.
After the defeat of Raph in the Lower Echelon of the Circle of Indulgence, a spectral projection of Aamon will appear in Rosehill Tower alongside Furgil. After affirming that Psaro's goal really is to slay Randolfo and stating that he is too weak to do so yet, Aamon asks if he has ever heard of the Secret of Evolution before and informs him that his underling Dr. Helix Helix is conducting research on the phenomenon at his laboratory.
Aamon and Furgil next appear during the raid on the Hidden Valley, hovering high above the secluded village as Dolph's forces raze the place. Once Psaro, Duffer, and Eileen emerge to inspect the ruin after the horde leaves and Psaro points out that the slain Hero was most definitely a fake, Aamon announces his presence. Here he manipulates Psaro via fear-mongering, highlighting how even common humans are willing to lay down their lives for the sake of the Hero and that if he were to unite with the other Chosen Ones then they would doubtlessly form an unstoppable force. This forces Psaro into a trap, thinking he can only use the Secret of Evolution to overcome the Chosen Ones, as shown when the prince next speaks with Rose in her room.
The wicked one's plan comes to fruition when he hires human thugs to kidnap and brutalize Rose, as in the original game. In order to buy them time to bring her to near-death, Aamon trained a succubat to perfectly master the Morph spell so finely that even Rose's ruby tears were replicated. Installing the deceiver in Rosehill Tower, the plan was set awry by the return of Toilen Trubble, who had slipped into the tower earlier in the hopes to reconcile his friendship with Psaro and witnessed the kidnapping whilst hiding from the bruisers. Aamon works this into his plan, however, instructing the succubat to pin him as the ringleader of the thugs. Having run off to warn Psaro and not witness the infiltration of the fake Rose, Toilen rightfully accuses her but is unable to explain her ruby tears. He leaves frustrated and defeated, with the fake Rose then occupying Psaro's time until a messenger bat is sent her way to in form her that her role is finished. The succubat reveals herself and gloats as Psaro sprints off to save Rose, killing her kidnappers but failing to reach her in time to save her from her wounds. The story then plays out as it first did in the original game with Psaro using the Secret of Evolution to become a hideous abomination that lays waste to all Nadiria, with Randolfo and Dolph presumably being killed as well, before he is slain by the Chosen Ones.
Whether Aamon survived Psaro's onslaught against the demon world in this scenario is never elaborated upon, but it remains irrelevant thanks to a certain sticky fingered human undoing his intricate machinations with one single act of thievery.
Toilen had filched a sample of the Sands of Time from Dr. Helix Helix prior to his abandonment of the group much earlier in the story, and used them to rewind time for himself and Psaro to the moment of truth in Rosehill Tower. The duo confront and defeat the impostor, who calls out for Aamon in her death moan. They race off to save Rose before she is beaten to death, and the trio sets out to confront the self-styled mastermind in his lair at the Upper Echelon of the Circle of Caprice.
Aamon is shocked and outraged that his scheme has been exposed, but deduces that the Sands of Time played a part and attempts one last shot at emotional manipulation by revealing that he is the one who turned the elves of the Circle of Caprice into stone golems to be his slaves, and delights in telling the trio that they are thus responsible for killing so many of Rose's kind. Aamon declares that the trio deserve nothing short of death for sullying the dawn of his new era, and launches a counterattack.
Unable to win in a straight fight, Aamon severs his connection to the Circle of Caprice and slips away as his sanctum crumbles. While the trio is occupied with the revelation of the true nature of the circle, Aamon steals the Armlet of Transmutation from Dr. Helix Helix. Aamon and Furgil then attempt to offer the talisman to Randolfo in the hopes that Dolph will be dumb enough to fulfill Psaro's role and wear it to gain more power. Randolf instantly sees through this deception and coldly explains that Aamon is not so clever as he thinks he is, with the tyrant explaining that he had already discovered the secret and perfected it himself. Demonstrating the effects of the Supreme Secret of Evolution to humiliate his scheming subordinate, Randolfo signals Dolph to kill him.
Aamon seemingly discovered the Secret of Evolution and became aware of it's mind-rendering flaws in the ancient past, during his raid against the elven kingdom of El Zetta. His initial goal was to steal the elves' time & space altering crystals known as travelite and chronocite, but would then curse the Queen of the El Zettian elves into becoming the Circle of Caprice itself while her people were transformed into stone golems. These mindless slaves would then mine for the penteractic crystals necessary to create the secret, under the watch of his subordinate Petrarch, insuring a steady supply of material with which to experiment with. These experiments did not bare fruit, however, and it would only be Randolfo who perfected the technique centuries later.
With this in mind, Aamon's plan hinges upon the emotional manipulation of Psaro, taking pains to trick the half-human prince into thinking that the Secret of Evolution is the only way to achieve his goals. It would not matter if the secret would destroy Psaro's mind as long as he killed the royal family before being slain by the Chosen Ones, whom Aamon was doubtlessly arrogant enough to think he would be able to defeat if he attacked them while weakened after their battle.
Ashtaroth (究極エビルプリースト Kyūkyoku Ebirupurīsuto)
