Doomsday: with unlimited warehouse system

David conducted a thorough search of the supermarket, making sure not to miss any zombies hiding in corners. Sally followed behind him, trembling with fear, and she realized that within just a few minutes, there were almost no living people left in the supermarket.

The man they encountered earlier seemed to be the last survivor in the entire supermarket. David wasn't surprised by this. That's the terrifying nature of the zombie virus—it spreads incredibly fast. Some estimates suggested that after just one month of the virus outbreak, only around 20% of the world's population remained.

It was an exaggerated number, and it would continue to increase over time. David skillfully killed the zombies in the supermarket, each strike efficient, precise, and deadly. There were no flashy moves, just simple and swift kills. Soon, David and Sally reached the corner of the supermarket entrance. Both of them could smell the thick scent of blood in the air.

As they turned the corner, David looked toward the supermarket entrance. Even though David had survived in the apocalypse for many years, he couldn't help but furrow his brow at the scene before him. The entrance was piled with countless corpses, blood flowing like rivers, staining the ground red. Limbs, organs, and intestines were scattered everywhere.

Dozens of zombies were "feeding," occasionally turning the bodies into new zombies. They joined the ranks of the undead, dragging their maimed bodies. At first glance, there were no living people left at the supermarket entrance. It seemed that only a few lucky ones had managed to escape. But even if they escaped the supermarket, there were countless zombies waiting for them outside. "Wow!"

Sally couldn't hold it any longer and vomited. Even after emptying her stomach, she continued to dry heave. The zombies that were feeding were attracted by the commotion caused by David. They abandoned their "food" and roared as they charged toward David.

David showed no fear. He wielded his alloy sword and approached, killing one zombie after another as easily as cutting melons and vegetables. With each swing, a zombie fell. But the number of zombies was still too high. One zombie grabbed David from the side and bit his shoulder. However, David's armor was a heavily customized piece, and human teeth posed no threat to it.

The zombie's bite had no effect and instead shattered its own tooth. While this zombie held onto David, others took the opportunity to swarm and grab his body. "David!" Sally exclaimed. She looked around, grabbed a nearby fire extinguisher, and wanted to come to David's aid.

But she quickly realized that David remained motionless, as steady as a rock. It was the powerful physical enhancement brought by the genetic modification serum. Although surrounded by zombies, he showed no panic whatsoever, let alone the fact that these zombies couldn't break through his defenses.

David grabbed one of the zombies behind him and threw it over his shoulder, slamming it hard onto the ground. Then, he stomped on the zombie's head, crushing it completely. Red and white substances sprayed out, blossoming into a bloody flower on the floor. Afterwards, David grabbed another zombie that had been clinging to his body and threw it away like a chick, knocking over a pile of zombies in the process.

David turned his head and shouted to Sally, "Don't come over, take care of yourself." Sally watched as David effortlessly threw the over 100-pound zombie away, almost dumbfounded. Was this truly the strength of a human?

After dealing with the zombies surrounding him, David continued his pursuit, swinging his alloy sword relentlessly. Like cutting wheat, the zombies fell one after another. Within just a few minutes, dozens of zombies were quickly eliminated by David. After handling everything, David walked to the supermarket entrance and glanced outside.

The streets were filled with fleeing crowds and stranded vehicles. Faint flickers of fire could be seen in the distance—overall, it was a scene of chaos. David closed the supermarket door to prevent other zombies from following them. "Aren't we going outside?" Sally's voice came from a distance. David shook his head. "Go outside? It's not any better out there now, and I have other things to do."

David walked to a zombie's corpse and pressed the tip of his alloy sword against its forehead. As the blade sliced through the skin, a white crystal appeared beneath it. "I didn't expect even these stage zombies to have mutant crystals."

David used the tip of his sword to pick out the crystal and carefully examined it in his hand. "No mistake, this is a mutant crystal, just a bit smaller." Some zombies and mutant creatures generate these crystals after undergoing mutations. Awakened individuals with special abilities can enhance their own powers by absorbing the energy from these crystals.

The more powerful the zombie or mutant creature, the stronger the energy contained within the crystal. However, these crystals have no effect on ordinary people. Well, it's not entirely accurate to say they have no effect. If an ordinary person were to directly consume a mutant crystal, they could strengthen their physique and even have a minuscule chance of becoming an awakened individual.

But in doing so, the greater likelihood is that they would mutate into a zombie, and the process is excruciatingly painful. Therefore, it's an extremely high-risk approach. So, it's not a problem to say that mutant crystals have no effect on ordinary people. This post-apocalyptic world is just that unfair to ordinary people.

In his previous life, David had also collected many mutant crystals, but he never attempted to consume them. Usually, he would sell these crystals to those awakened individuals in exchange for resources. However, there were also some unscrupulous awakened individuals who would simply snatch the crystals without giving any compensation. David had no way to deal with such matters, as awakened individuals were not someone he could afford to offend.

David waved his hand at Sally. "Come here." Sally walked slowly to David's side, unsure of what he was going to do. David handed her the alloy sword in his hand and then shook the mutant crystal in his hand. "Open the foreheads of these zombies, collect these crystals, and be quick about it."

Sally was momentarily stunned. "Me?" David coldly said, "What's the matter, unwilling?" Sally hesitated for a moment, lowered her head, and fell silent. After a brief silence, she picked up the knife and started searching for the crystals on the corpses scattered on the ground.

At that moment, a voice rang in their ears, "Emergency notice, attention please!" Both of them were drawn to the voice on the television and looked up.