When the Red Moon Demon Lord invades the Starter Village, exhausted Starfell Guild members crumble and the wounded leader forces a lone volunteer to block the demon commander. Frank Collins, a level-one player who entered the game to raise money for his sick sister, is shoved into combat and mocked as cannon fodder. Facing certain death, he panics—then a system appears: the Starter Village Invincibility System grants a 99,999,999 boost inside the village but cuts power to one and forbids leveling once he leaves. Frank accepts; his invincibility saves him, but his future growth is locked.
During a chaotic battle, a man mutters "I'm actually invincible" as enemy fighters keep attacking him. Instead of fleeing when others shout to run, he moves straight toward the demon commander. Soldiers panic while he charges with a wooden sword. Observers react and someone yells, "System, don't mess with me!"—then the unthinkable happens: the demon commander falls dead. The sudden death overturns expectations, leaving the protagonist and witnesses stunned and confronting an impossible outcome with no answer yet for how the commander was killed.
The Red Moon Demon Lord personally attacks the town, forcing defenders to fall back to the fortress as he demands submission with crushing pressure. Suddenly a supposed level-one from the Starter Village refuses to be cowed and executes a slick counter, even slapping the Demon Lord, that leaves observers stunned and recalls he earlier killed the demon commander. As the Demon Lord's aura abruptly vanishes, the City Lord traces the power toward the Starter Village and orders his forces to find this outsider master at all costs, launching a desperate manhunt.
Mr. Collins suddenly returns after defeating the Red Moon Demon Lord, and the Starfell Guild’s repentant members grovel and pledge to follow him. The guild expects massive XP and loot, but the Starter Village Invincibility System permanently locks their levels, dashing those hopes. The demon lord dropped a Red Moon Core that is leaking energy and corrupting the land, so members urge Collins to lead them to Oath City for purification by the city lord’s royal mage. Collins seizes the chance for a reward and accepts leadership. They set off toward Oath City with the unstable core, the outcome unresolved.
He is about to leave the Starter Village when the invincibility buff warns that all attributes will revert to 1 outside. Afraid he'll be helpless, he initially refuses to step out and talks of retiring. Then a main quest triggers: Purify the Demon Core—deliver it to Oath City for purification, reward: one Invincibility Trial Card. He imagines using invincibility to slay demons and save his sister, but feels the world's fate is everyone's responsibility. He decides to take the quest; someone volunteers to tag along—yet stepping beyond the barrier will drop his power to 1.
After the Starfell Guild defeats the Red Moon Demon Lord, a low-level guild member finds divine-tier loot but the system bars equipping it due to his level. He frantically tries gear, only to be told repeatedly, "Your level is too low." Guildmates shower praise on Mr. Collins, who refuses the items as trivial; the group splits the spoils and one longsword raises someone's combat power by 600, pushing them past 1000. The narrator realizes Collins already outclasses gear. Left unable to equip and still level one on a monster-filled road, he must figure out how to keep up the act.
A gang waits on a mountain to ambush and rob a group of level-one players, mocking their target as "level-one trash" and ordering men to take their gear. Suddenly a man in full, legendary Holy War Armor appears—the supposed victim is actually a powerful guild leader, Mr. Collins. The bandits freeze, plead for mercy and offer all their belongings. When a follower asks, "kill them or let them go?" Collins refuses to finish them, calls them pitiful, and lets them go. The episode closes with one man protesting, "I didn't mean it like that!"
While the group pauses to discard 'trash' loot, Mr. Collins suddenly falters and admits he has a confession. He reveals—and the others realize—that he used the legendary Wind Ear to sense an orc ambush ahead. Collins seizes control: Will forms a defensive line and Mike scouts forward. As the team braces, Collins drops his restraint. "Guys! Attack!" he orders, and an assault erupts. The team is stunned by the sudden offensive, leaving the immediate battle underway and the outcome unresolved as the group rushes into chaos.
Under a sudden ambush, soldiers and mages struggle to protect Mr. Collins as enemy numbers overwhelm them and magic and stamina dwindle. Mr. Collins, furious, signals them to stop attacking; his words are taken as a tactic: feign weakness to lure the enemy's final all-out charge. The unit forms a defensive circle, lets the foe commit, then launches a coordinated counterassault and begins to break the attackers as their stamina collapses. Survivors hail Collins's command afterward, but he quietly confesses he nearly wanted to surrender earlier — a revelation that leaves his leadership under instant scrutiny.
At the City Lord's manor, Mr. Collins and his escort Sharon are stopped by guards who insult him and order them out. Sharon insists Collins killed the Red Moon Demon Lord, but a level check shows his level and combat power are 1, drawing ridicule and calls to banish them. Officers move to arrest the group, yet the City Lord recognizes Collins. The Archmage begins purifying the Red Moon Core Collins brought, and the City Lord awards him a badge that can claim any mansion. Collins plans to use it for his sister's medical bills—then someone shouts, 'Stop!'.