Klaus, a college student whose only real passion was the serialized web-novel game Artemis Online, found his mundane life abruptly shattered. He rushed to download the long-awaited sequel, thrilled by the developers' reward of a mythical Legendary Spin Ticket. His anticipation for a legendary heroine or weapon was immense, a payoff for years of dedicated play. But the gacha wheel delivered a cruel punchline: he pulled an average-looking character named "Klaus," a First-Class Wizard Apprentice with the worst possible stats and a forgettable face. This face-slap moment of receiving a worthless mob character was immediately followed by a brutal, mundane death: a stray gunshot in a college bathroom. He then reincarnated, not as the game's protagonist or a powerful villain, but as that very same pathetic NPC, Klaus, now broke and facing a world where his meta-knowledge was his only asset against his abysmal stats. This ultimate reversal left him at rock bottom, contemplating desperate measures, until the Ultimate Gacha System, the very mechanic he knew so well, materialized before him, offering a glimmer of hope in his bleak new existence. This desperate trigger sets the stage for his fight for relevance.

With the Ultimate Gacha System activated, Klaus received two crucial spins. His first draw was a Resonance Boost Potion, a legendary item he'd never encountered in the game, promising to elevate his "Red Resonance"—a wizard's death sentence—to a respectable "Blue" tier. Consuming it plunged him into a violent, spasming transformation, purging black impurities and leaving him subtly changed, physically lighter and with a significantly improved mana capacity. His second spin landed on Magnetic Field, a Tier 2 spell that granted potent control over metals. These were game-changing cheats, yet the world immediately reminded him of his place. A carriage splattered him with mud, forcing an exhausting 500-floor climb, and the Adventurer's Guild receptionist, Astrid, treated him with disdain due to his commoner status. Even with powerful magic, his physical weakness and lack of resources were glaring. He paid for his Adventurer's Guild registration with his meager savings, only to realize he was still pure cannon fodder, completely lacking combat ability, desperately needing to prove himself in the perilous Galen Dungeon.

Klaus's first foray into the Galen Dungeon's second floor was a humbling experience. Despite his extensive meta-knowledge, his physical ineptitude with a sword was immediately exposed by a mocking slime, delivering a comedic yet painful face-slap. This forced him to rely on his newly acquired Metal Magic. He used Magnetic Field to impale the slime with a sword, a first successful combat application. The dungeon quickly escalated, introducing Dire Wolves and then an Armored Spider, a Tier 2 monster that had already decimated other adventurers. Klaus, combining his game knowledge with Magnetic Field, repurposed scattered battlefield scrap—swords, arrows, chainmail—into a lethal barrage, focusing on the spider's weak underbelly. He triumphed, killing the formidable beast, but immediately collapsed from severe mental exhaustion, revealing the critical limitation of his new powers. Returning to the Guild, he downplayed his feat, securing a D-rank and significant gold, but a new setback emerged when Taula, the herb shop girl, revealed she'd accidentally destroyed the very herbs he needed, forcing him into another perilous expedition to Yerefall Grove.

The journey to Yerefall Grove, a mini-dungeon, introduced Taula, a superhumanly strong yet incredibly forgetful A-rank adventurer. Her chaotic nature led to a series of comedic and terrifying encounters, from fighting worm-infested herbs to accidentally angering a giant snake, forcing Klaus into desperate sword-surfing escapes and even enduring a punch to the face after a cleansing spell. This expedition, despite its absurdity, culminated in Klaus successfully merging his gathered herbs into a legendary Tri-Essence Spirit Root, dramatically boosting his stats to Second-Class Wizard Apprentice with Indigo Resonance. Soon after, he joined the Phantom Crew for a resource dungeon raid, where his Metal Magic proved invaluable, unearthing immense wealth in Metil Diamonds. However, the discovery of such riches ignited Kahn, the crew leader's, profound greed. He brutally murdered Vex and Garrick to secure the treasure for himself, leaving Klaus and Serra trapped, facing Kahn's monstrous betrayal. This gut-wrenching turn revealed the brutal, lawless reality of dungeon life and the corrupting power of wealth.