Regressed with Omnipotent AI on Zombie Apocalypse

"Analyzing target..." Ego's voice echoed through the comms. A moment later, he added, "Analysis complete. This creature is a domesticated pet, an orange tabby cat, part of the felidae family. It has mutated due to unknown causes, drastically increasing in size and becoming highly aggressive."

Zack's jaw nearly dropped. "A... house cat? An orange tabby cat?!"

Ego's words shattered his sense of reality. The two-meter-long monster in front of him, bulging with muscle and radiating deadly intent, had once been a simple orange tabby—an overweight cat that could barely move.

"Sir, caution advised. This creature is extremely dangerous," Ego warned again. Zack’s heart raced as he processed the information. Unlike regular zombies, animals infected by the Zeta virus seemed to retain disturbing levels of intelligence.

The zombie cat, now the size of a tiger, didn’t pounce immediately but waited at the door, locking eyes with Zack with bloodthirsty focus. It wasn’t attacking yet—it was sizing him up, sensing the threat posed by the shotgun in his hands. It paced back and forth, eyes narrowed, wary.

Zack tightened his grip on the shotgun, his instincts telling him not to fire recklessly. He knew how fast a cat’s reflexes could be, and a creature this size would be even faster. If he missed, there might not be a second chance.

“The optimal battle plan is now being simulated,” Ego’s voice cut through his thoughts. Virtual figures appeared in Zack’s view—digital representations of the convenience store and simulations of the zombie cat’s possible movements. In each simulation, the human figure was mauled by the beast, only a few scenarios ending with Zack surviving. However, those plans involved risky moves that left him seriously injured, and Ego quickly discarded them.

Finally, Ego spoke again. “Sir, I’ve calculated the best course of action for a safe outcome.”

The entire process took less than five seconds, but to Zack, it felt like an eternity.

Instantly, all the virtual figures vanished except one—a single projection in front of Zack, outlining the precise steps to avoid and counter the zombie cat. It was like having a perfect game walkthrough laid out right before him.

Every move was clear and annotated: where to step, when to dodge. Even as Zack mentally prepared, the zombie cat decided it was time to attack. The caution in its eyes turned into primal hunger, and with a guttural snarl, it charged forward, faster than a ghostly blur.

Zack braced himself, already one step ahead thanks to the virtual projection. He pulled the last Molotov cocktail from his backpack and, without wasting a second, tossed it, not even bothering to light it first. Following Ego’s guidance, he dodged left, throwing the bottle into the spot where he had just been standing. The bottle shattered, spreading flammable liquid across the floor.

The zombie cat’s claws narrowly missed him, slicing through the air with such force that it left a breeze past his cheek. Under Ego’s calculations, the dangerously close encounter turned into a perfect opening for Zack. The cat slipped on the spilled alcohol and shards of glass, crashing to the floor with a thud.

As it struggled to rise, shards of glass embedded in its flesh, its fur soaked in alcohol.

“Die, you brute!” Zack snarled. He grabbed a handful of cheap lighters from the counter, tossing them toward the dazed cat, before aiming his shotgun.

Bang!

The powerful recoil made his hands tingle as the blast sprayed steel balls into the creature, igniting the lighters mid-air. Flames exploded instantly, spreading across the alcohol-soaked zombie cat. It was engulfed in a violent blaze, thrashing around and letting out an eerie, guttural hiss. The resilience of undead creatures was terrifying; although they felt no pain, this one seemed to have enough sense to fear fire.

As the flames roared around the beast, Zack seized the moment and fired two more rounds. Each blast tore into the cat’s body, spraying dark, foul-smelling blood. The creature staggered, nearly collapsing, but it wasn’t done yet.

Suddenly, Ego’s simulation flashed a warning. The virtual image of Zack dodged to the side, and Zack followed instinctively, leaping away from the counter just in time.

The zombie cat, now a charred, rage-fueled shell of its former self, charged in one last, desperate attempt to attack. It slammed into the counter Zack had just left, splintering it into pieces. The flames spread to papers and other items around, intensifying the inferno.

“Almost had me there,” Zack muttered, cursing under his breath.

The zombie cat’s twisted body struggled to rise again, its red eyes blazing with hatred. Zack realized he had one final opportunity. He grabbed a heavy, industrial-sized fire extinguisher from the nearby fire door, feeling the weight of it in his arms, and swung it down onto the cat’s head with all his strength.

The beast staggered back, stunned, and its movements slowed for precious seconds. Zack wasted no time. He sprinted outside, and once he was at a safe distance, he turned, aiming his shotgun—not at the cat, but directly at the fire extinguisher still lying at the creature’s feet.

Zack’s cold smile grew as he watched the zombie cat push itself to its feet. He mimicked an explosion sound under his breath, “Boom!” and pulled the trigger.

Bang!

The shotgun blast was quickly drowned out by a much louder explosion. The shot hit the fire extinguisher, causing the high-pressure gas inside to rupture violently. The canister exploded, sending sharp fragments of metal flying in every direction. The zombie cat, caught in the blast, was immediately struck by the shrapnel. Jagged pieces of metal tore through its charred body, creating gaping holes. One fragment drove straight through its skull, ending its life for good.

Zack dropped to the ground, staying low until the smoke cleared. When he finally stood up, the convenience store was filled with a thick, blinding haze of dry powder. The explosion had not only destroyed the zombie cat but also extinguished the small fires that had been smoldering in the store.

“Ego, is it dead?” Zack asked, his gun still in hand.

“Analyzing… No signs of life detected,” Ego confirmed.

Zack exhaled in relief. "Alright, time to refuel and get out of here."

He moved quickly, knowing that the explosion would likely attract more zombies. Reaching the road, he climbed into the armored vehicle parked nearby and drove to the gas station. At the self-service pump, he filled the vehicle’s tank, then grabbed several barrels, filling them with over a hundred liters of extra fuel for emergencies.

By the time he finished, the white smoke in the convenience store had begun to dissipate. “Ego, keep an eye on our surroundings. Let me know if anything moves out there,” Zack instructed.

The area appeared clear. He changed his magazine, aware that he had used up most of his ammo during the fight with the zombie cat. With a fresh clip loaded, he approached the convenience store, bracing himself for any lingering danger.

As he neared, a strong, acrid smell hit him—the scent of burned plastic and singed fur hung heavily in the air. The cat’s lifeless body lay in the middle of the store, covered in dry powder, less gruesome than he had expected. Zack tore a strip from his shirt to cover his mouth and nose, stepping over the cat’s body and heading toward the back.

“Wait… someone’s still alive?”