Aaron Oster Books in Order

Arthur finds himself trapped inside a brutal version of his favorite game, where death is permanent. To survive the Animal Kingdom's unforgiving hierarchy, he must adapt quickly and gain strength before becoming another predator's next meal.

Unable to channel the power that defines his world, orphan Roy endures relentless abuse and menial labor within his adoptive clan. In a society where weakness can mean death, mounting desperation pushes him toward a chance to change his fate.

After his family is butchered, Arbor leaves home determined to reclaim what he has lost. His search takes him into a dangerous world of magic and monsters, where surviving requires more strength than grief alone can provide.

With a powerful enemy rising in the North, Morgan considers abandoning the Five Kingdoms. The discovery of more false memories instead sends him and Sarah toward a ruined city, searching for answers about his past and whom to trust.

An ancient creature created and sealed by Samuel has awakened, spreading devastation through the North Kingdom. Unable to intervene directly, Samuel considers a drastic response that could change the rules governing the Five Kingdoms as catastrophe begins.

Morgan and Sarah flee a spreading war, but mercenaries and assassins pursue them across the Five Kingdoms. A warning from a powerful being adds urgency to their escape, forcing difficult choices as their enemies close in.

An outcast nearing sixteen without awakened abilities, Morgan draws dangerous attention through his friendship with a lord's daughter. As her father plots against him, Morgan faces a decision that could transform his future in a world ruled by strength.

Rejected by the people he hoped to join, Arbor leads his gremlins toward a slave city in search of his sister. Elsewhere, an assassin stalks the elven capital as Karria faces threats that signal a widening war.

Zundy and his crew head for Cointown after betrayal disrupts their journey. To continue toward the Green Sea and the coveted Viridian Core, they must navigate criminal connections, changing plans, and the enormous Guardians blocking their path.

Threatened with death, Roy leaves the Crater only to face exile in the Wilds after Aika is captured. With powerful forces gathering and his own inner struggles unresolved, he must decide how to recover what he has lost.

Newly elevated to the nobility, Arbor hopes his status will help him find his missing sister. A village's plea for protection draws him into a carefully prepared trap that threatens to ensnare them both in deadly danger.

Morgan returns to Faeland with a weapon against the gods and a delegation seeking ingredients to reproduce its power. Meanwhile, disappearances and unnatural weather in the West Kingdom suggest a threat Katherine recognizes all too well.

As the barrier protecting the Five Kingdoms fails, Morgan prepares to enter enemy territory on a vital mission. Across the divide, Faeland's rulers ready themselves for war while gods manipulate events and ancient creatures begin to stir.

With the North nearly overwhelmed by Octagon's monsters, Morgan seeks help from the other kingdoms. Their rulers have feuded for centuries, and persuading them to unite may be the only way to prevent the remaining defenses from collapsing.

Morgan's latest victory brings little peace as old and new enemies gather against him. An unexpected attack leaves him isolated, facing difficult choices while war approaches and rising World Beasts threaten everything he has fought to secure.

After months of training, Roy and Aika accompany their powerful teacher to the Itachi capital. Rival clans, gathering beasts, and Roy's father's determination to reclaim him threaten their return to civilization and his next stage of advancement.

Stranded in the Windblight after escaping captivity, Roy faces a rival clan's fighting arena. Meanwhile, Aika and her companions struggle against retaliation from the Itachi clan as they search for their missing friend in hostile territory.

Roy enters a tournament whose outcome could determine the continent's survival, facing opponents far beyond his strength. An ancient book and unfamiliar senses may offer an advantage, but a disturbing new voice complicates his struggle for victory.

As an ancient beast and its armies threaten Buryoku, Roy and Aika travel to a distant land seeking a teacher who understands his birthright. Their search may hold the key to defeating the creature before war overwhelms them.

Returning to the place where his martial journey began, Roy struggles to understand his Core's unsettling behavior. To continue advancing, he must confront the past he hoped to escape and discover what is holding him back.

War consumes Faeland while battling World Beasts tear the land apart and drive its inhabitants from their homes. Morgan faces hostile agents and dangerous cultists, whose theft of something precious adds a personal urgency to the conflict.

Morgan and Sarah bring Faeland's survivors back to the Five Kingdoms as gods and monsters converge on their world. Facing his greatest test, Morgan must confront the forces of chaos before they destroy everything he hopes to protect.

With Buryoku's continents converging and demons advancing, Roy searches an ancient library for the secrets of his next advancement. Meanwhile, a mysterious array drains the Ancient Beasts, threatening a disaster even the Scions cannot prevent.

Cut off from home after a catastrophe, Roy and his companions seek a legendary figure on the devastated continent of Tero. When Roy becomes separated from the group, he must survive the underworld while demons target humanity's defenders.

Released demons and awakening Ancient Beasts threaten a transformed Buryoku. Newly advanced to Sage, Roy leads an isolated expedition into the Glacial Bands, racing rival factions to prevent another ancient monster from rising and overwhelming humanity.

After twelve deaths in other worlds, Keith renegotiates his bargain with an immortal for one final chance to reclaim his family. Sent to monster-filled Raiah, he must hunt its deadliest creatures or face an even harsher fate.

Keith travels to Umber City to investigate a dangerous guild member, expecting support from powerful allies. Assassination plots, competing quests, and a far-reaching conspiracy soon threaten his mission and his chance to fulfill the Trickster's bargain.

Keith prepares to confront Humania's most powerful monster, an imprisoned elder troll threatening widespread destruction. With his guild diverted to other duties, he must find the strength and support to continue the quest that could restore his family.

Keith travels to Beastland to pursue another World Monster, only to become entangled in a struggle among six ruling clans. An irresistible opportunity draws him deeper into their conflict, testing his abilities against dangerous quests and hidden plots.

Roy and his teammates face the tournament's strongest opposition with little chance of victory. He must uncover deeper reserves of physical and spiritual strength while ancient seals weaken, threatening changes far beyond the competition itself.

As demons intensify their attacks across Buryoku, Roy confronts danger outside the Ghost's Tower. Threats of civil war and a new Divine's emergence force him and his allies to test their limits with the world's survival at stake.

Dan awakens trapped in a lethal version of his favorite game, inhabiting a mysterious Chimera Newt. Surrounded by monstrous insects and oppressive feline rulers, he must master his unfamiliar abilities to survive a world far harsher than its virtual counterpart.

Training in a formidable dungeon after the northern war, Morgan gradually rebuilds his strength. A sinister presence deep in the Beast Zone threatens the lifeline he has been offered and his hope of seeing Sarah again.

After decades fighting through alien worlds, Nate discovers a portal that returns him to the beginning of humanity's catastrophe. Armed with hard-won knowledge, he must reshape events so his family and fellow survivors can endure the trials ahead.

With a planet's destruction approaching, Nate must prepare humanity to move to a dangerous new world. Portal ambushes and an emerging Dark Guild complicate his efforts to protect his family and keep his plans for survival intact.

The legendary Nemesis Dungeon opens, drawing Keith and rival clans into a race for its ultimate prize. Pursuing the Greathammer tests his leadership as well as his fighting skills, while outside factions and old enemies complicate the hunt.

With a battle against Beastland's World Monster approaching, Keith gathers resources to protect his newly recognized guild. Fanatical enemies, the Alchemist Guild, and a hostile Spirit threaten his preparations and his hope of winning back his family.

Keith enters the Fourliance facing powerful enemies and a warning about an unseen pursuer. As he establishes his guild, the discovery of an evolving weapon offers hope, but obtaining its materials forces a dangerous confrontation with an old adversary.

Born with a beetle's traits, Zundy has always been an outsider among his people. His coming-of-age journey sends him toward the legendary Viridian Core, through strange lands where powerful Guardians stand between him and his ambitions.

Fifteen years after the war, Morgan and Sarah's daughter leaves for an elite academy. Their apparent peace begins to unravel as Morgan's visions grow clouded and hidden enemies prepare a new threat to the Five Kingdoms.

Political upheaval reshapes the Fourliance while Keith searches for its World Monster and builds his guild. A disastrous raid brings an ultimatum from a superior enemy, sending him on urgent quests for a weapon that might restore the balance.

Stranded in Necro-Beast territory, Keith fights through undead forces while his enemies consider joining together. Ahead lies the Terror Queen, a cunning World Monster whose defeat will demand more than the strength that has carried him this far.

Before venturing into the monster-filled Frigid Seas, Keith must settle unfinished business and strengthen another branch of his guild. Growing threats and mounting responsibilities complicate his preparations for a frozen continent that promises his toughest challenges yet.

Keith and Selena search for a hidden route into a formidable stronghold as monsters begin behaving strangely. A terrifying encounter forces Keith onto a dangerous path, while distant enemies form an alliance that could overwhelm him.

To save his suspended world from destruction, Craig must complete an immortal's quest in a strange new realm. His bitter rival seeks the same prize, forcing Craig to master monster abilities and turn centuries of experience into survival.

Craig and his companions leave their village for a larger city, hoping to escape a growing threat. Discovering a royal elf's body and an alarming letter pulls them toward a danger that could destroy the continent and his quest.

With Morgan trapped in a Divine Zone, Gwen must rescue her brother and friends from an isolated academy. Blocked communications and teleportation leave Sarah and Katherine struggling to respond as danger spreads and time runs out.

Keith stands between Layman's Turf and three overwhelming threats: a terrifying enemy, a Doomfire Dragon, and a World Monster. Protecting the city requires confronting all three at once, testing whether his accumulated strength can withstand their combined assault.

A primordial force threatens the System's authority and blocks Keith's route to Monstros. Before entering Raiah's most hostile continent, he must gather allies, prepare elixirs, and survive an enemy whose power overshadows the Frigid Seas.

Keith pushes deeper into Monstros in pursuit of the final World Monster. Rival powers gather followers and plot against him, while hostile Spirits send their avatars to challenge the strength he needs to complete his quest.

Heavyweight champion Hank is summoned to another world by royals who expect him to fight their demon war. Refusing to become their pawn, he must navigate an unfamiliar system of power while defending his independence against coercion.

The adventure continues in the second installment of Path of the Unconquerable, Aaron Oster's progression fantasy series.

Morgan must escort Gwen and her friends through a Beast Zone whose environment is deadly. While he struggles to get them home, an invasion takes shape and a vengeful Pinnacle King threatens the kingdoms he cannot reach.

To reach the last World Monster, Keith must overcome the formidable guardians of the World Wall. New discoveries reveal Monstros to be larger and stranger than expected, while hidden Inquisitors prepare to end his journey permanently.

Keith and his allies venture beyond the Wall in search of the final World Monster. Ancient secrets and unfamiliar creatures complicate their approach to the Overbeast in the opening half of the series' two-part concluding adventure.