A Hell Crystal was the core of an infected, the source of all its unnatural characteristics. Basically this tiny crystal was the battery that made these abominations work. Similar to Gehenna the nature of this object was unknown however in the future a scientist revealed one of his secrets. He could have saved humanity if he had more time to develop that idea but unfortunately he died along with his investigation.

This object was normally located in the torso of the infected, if it was not removed after killing it the creature would be revived in a couple of days regardless of the state of the corpse. Due to this phenomenon in the previous timeline during the first year of the pandemic people believed that the only way to permanently eliminate these abominations was to burn them. That's why the practice of having huge piles of corpses and setting them on fire became quite common until someone realized that these crystals were found in the remains. It took humanity 2 years to learn that the Hell Crystals were the key to their survival, that delay turned out to be a fatal error in the war against the infected.

The method to use them was simple, they simply had to be ingested in some way. Swallowing them directly or grinding them to be inhaled were the most common methods because of their horrible taste. Once that is done your body will begin to evolve to survive in this new world, the more crystals you consume the stronger you become.

Human evolution, like that of the infected, was divided into three known stages. In the first one it is only possible to improve your basic skills such as run faster, increase your physical strength, your senses, etc. In the second phase you get a class with powers that many consider magical. Examples of this would be Spirit, Vampire, Beastman, Homunculus, etc. Finally, in the third stage the individual would gain the ability to control and create a type of matter or energy such as heat, electricity, earth, water, fire, magma, steel, etc.

The problem is that to pass each stage you need a Hell Crystal of the corresponding level. Consuming a Hell Crystal level 1 will give you experience in your first stage but in the second and third you will be useless. Because each stage is exponentially stronger, people naturally hurried to get to the third as fast as possible. While at first that seemed like the best tactic, it proved to be quite problematic because they lacked a strong base to maintain all the skills that the third phase gave.

With the Hell Crystal in his hands Gabriel hurried back to his apartment and created a barricade on his door with some furniture. The absorption process is slow and while he was doing it he was totally unprotected so finding a safe place to do it is essential.

He took off all his clothes because the mutations could alter your anatomy and break your clothing. He crushed the crystal in to dust and using one of the bills in his wallet snort the dust quickly. After that the hallucinations began to occur. A sphere of flesh and bone with words painted in blood appeared in front of the man, by interacting with this you can alter your body with a random beneficial mutation. But Gabriel knew how to refine this process so that his evolution was easier to perform, molding bones, weaving flesh and painting with blood he created a much easier interface to use.

Now it was a book with several mutations described in which he could choose. As if it were a videogame this hallucination allowed him to dictate how his body will evolve. It took 5 years to perfect this method and completely eliminate chance. Now with this advantage it would be much easier to adapt to the apocalypse.

Dozens of different options were before him, of all these roads he had to choose carefully the right one. He thought carefully and came to the conclusion that what he needed most was extra time. Was there any way to add more hours to a day? The answer was yes. The mutation he chose was "Sleep efficiency".

Gabriel evolved:

Sleep efficiency 1:You only have to sleep 4 hours per day.

Gabriel still had to rest but now he had 4 more hours that he could use to study the documents in his phone. In his previous life he was quite good at making various types of weapons and armor, which is why he wanted to improve in other things now that he had the opportunity. Medicine would be his object of study, after all the only doctor who isn't infected was 2000 kilometers from here. After selecting the mutations of the book it disappeared.

Once again in the real world Gabriel sighed feeling the change in his body that fortunately was not accompanied by any change in his anatomy. He put his clothes and his weapons back in order to continue cleaning this floor, he still had two other departments to scavenge.

Methodically he dismantled the barricade, approached another department and repeated the previous process. There was another infected in this one, a pretty thin woman to be exact. Like a machine he killed this beast using his club and then dedicated himself to finding another crystal in its entrails. He still needed two more to get his next mutations, so he tried his luck on the last department.

For his fortune this seemed to contain another zombie but something unusual happened when Gabriel opened the door. This infected man was considerably faster and more agile than the previous ones. Seeing the speed of the beast, he could identify in an instant that he was a Runner. Some zombies mutate and become extremely dangerous varieties before time and this was one of these. Unlike the standard zombie, these have a speed that borders on the inhuman, being able to run at 40 km / h permanently. The creature rushed to the survivor and him hit it in the head with the homemade club but due to its lack of durability it broke in half. Sadly it was only enough to knock him down on the ground, and he quickly started to get up.

As a veteran Gabriel instead of escaping he grabbed the piece of wood that used to be his club and used it as a stake to strike again. With a quick movement the survivor impaled the runner in the skull ending with his life.

He was breathing heavily, looking around as he pulled out his kitchen knife in case of another surprise. It was not the best weapon against the infected but it was better than nothing. He went inside the apartment checking if there was any other zombie but what he found surprised him.

In a cage there was a cat that seemed to have recently been castrated. This animal had brown hair with some yellow spots, no doubt a pretty cute specimen. But what really surprised Gabriel was the fact that the cat didn't seem to have any symptoms of the infection.

The infected animals are one of the biggest problems for the survivors especially in Buenos Aires. The huge population of mutant stray dogs made the streets deadly traps, the cats turned the task of moving between the roof and roof too dangerous and the rats transformed the sewers into hell. That's why Gabriel had acquired a natural aversion against animals but seeing what was possibly the last healthy cat on the planet he felt some mercy.

He searched the department for a can of cat food. When Gabriel found it he took out one of his crystals. He mixed the two together and then give it to the animal that was locked in its cage.

-Look I can't take care of you but at least with this you will have more chances to survive- After that he went looking for the Hell Crystal in the Runner corpse. It was a silly decision based purely on emotions but if Gabriel had been an intelligent person he wouldn't have died in the first place.

Michi evolved:

Awakened:You are a smart boy now.