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The ability to enlarge oneself is, scientifically speaking, a self-destructive ability.

For example, suppose one’s height becomes ten times greater. That is a tenfold increase in length.
In contrast, body weight is length x width x depth = 10 x 10 x 10 = 1000 times.
Muscle strength is determined by cross-sectional area, meaning width x depth, so 10 × 10 = 100 times.

Your weight becomes 1000 times, but your muscles become only 100 times stronger. It’s the same as your weight becoming ten times heavier while having only your original power.
Imagine a grown man 170 cm tall and 650 kg in weight, you’d see how inappropriate this is. It’s far beyond obesity. His sagging fat would be so heavy that he couldn’t even stand up, let alone walk. He wouldn’t have the leg strength to lift his own body.
Furthermore, even doing nothing, the load of his own body weight would damage his heart and respiratory system, and he would eventually die.

This is the very reason why mice have thin legs and elephants have thick ones.
A mouse is small, so even thin legs can support its weight. An elephant is big, so unless it has short, thick legs, it cannot support its weight.
If you gigantified a mouse to the size of an elephant, its legs would be crushed the moment it enlarged, shattering in complex fractures.

Therefore, the gigantification ability can be considered a self-destructive ability. Just by gigantifying, one becomes unable to move and dies. In contrast to how powerful the word “gigantification” sounds, the bigger one becomes, the weaker the ability becomes.
…Scientifically, speaking.

Now let’s consider Huang-hu the tabby cat.
Huang-hu is a gigantification ability user. When he uses his ability, he becomes big—neat and simple.
His initial specs is that he increased his height by 1.5 times, activation duration 20 seconds. For 20 seconds, he can become a cat about two sizes bigger. Even enlarged, a cat is a cat. Nothing strange about that.

After a day of growing pains, two days later, Huang-hu demonstrated a gigantification ability of height 2.3 times, activation duration 20 seconds. A growth rate of 1.5 times per cycle. While using the ability, he becomes a huge body on the level of a Doberman.
Big. As a cat, he is outside the standard. So big you’d doubt your eyes.
Looking it up, at this stage he had already slightly exceeded the Guinness World Record for largest giant cat in history. Up to this point, he was barely still a cat. The moment you saw him, you’d be shocked, thinking “A cat!? Huge!” but still a cat.

However, two days later, when he reached 3.4 times, he became a size no cat could explain.
No longer cat-sized. Not even dog-sized. A bear-sized, if anything to compare him.
Huang-hu had become a large creature at the level where you would feel uneasy facing him without iron bars between you.
In fact, he was actually seen by a human and caused an uproar. While gigantified, he opened the heavy iron lid of a restaurant’s back-alley trash bin to rummage inside, and an employee taking out the trash saw him.

Fortunately or unfortunately, the incident happened at night in a dim back alley, so he wasn’t clearly seen. Mistaken not for a cat but for a bear that had come down into town, he was reported on the next morning’s news, and the hunting association was requested to mobilize.
However, despite an intense search, no trace of the bear was found. Not even any foot prints. It didn’t appear on any of the surveillance cameras installed throughout the city. The camera behind the restaurant had actually captured a large furred creature with a tail however, so it wasn’t a false report. The bear had vanished without a trace.

The bear incident that had unsettled nearby residents had its search called off a week after discovery, and the authorities announced, “The bear returned to the mountains. We will strengthen measures so that bears do not wander into the city again,” marking a temporary resolution.
No one would imagine that the truth behind the mysterious bear was a cat gigantified by psychic ability. Although Huang-hu’s panicked escape after frightening the employee was clearly recorded on camera, at the moment the gigantification was released, the surveillance camera was blocked by a plastic bag blown by a sudden mysterious gust of wind, so no one could connect the bear to the cat.

Even when gigantified to bear-size, Huang-hu can display the same agility as before gigantification. His thinking ability and durability remain unchanged. He simply becomes big, and his power becomes fitting for his appearance. Although he should crumble under his own weight, he does not, and no abnormalities in his condition appear.
It’s realistically impossible, yet it occurs. That is precisely why psychic ability, which ignores physical laws, is called “super”powers.

Considering the hunting-association mobilization, I strongly warned Huang-hu to use his ability secretly. Especially to avoid making enemies of humans.

Growing large doesn’t mean Huang-hu suddenly becomes invincible. His fur can still be cut with scissors. A knife would stab him just fine, and he would bleed like normal.
Of course, his subcutaneous fat and muscle become thicker, so light attacks won’t reach vital organs or blood vessels, and his endurance is increased. But a shot from a hunting rifle would seriously injure him, and escaping a bear trap would be difficult for him.
Even if the gigantification multiplier keeps increasing until he becomes the size of a building, humans have means to destroy buildings. Even if he becomes as large as a mountain, humans have means to burn down mountains.
The gigantification ability is a conspicuous ability, the exact opposite of stealth. If humans learn of his existence and deem him dangerous, he would be killed, or captured and used as an experiment.

No matter how astonishing the ability, opposing humans carries too large a risk. Then again, if he grows to the point he could destroy the sun, then that’s another story.

After becoming able to gigantify to bear-size, Huang-hu rapidly expanded his influence in the stray-cat society of Qitaohe City.
“Big” is a very easy-to-understand form of strength. You can tell at a glance.
Just by showing his gigantification, every stray cat he encountered surrendered without a fight.
There were also strays who disliked the house-cat faction (Tai-yi), who was using the universal translation ability to skillfully negotiate with crows and absorb the stray-cat faction, and voluntarily submitted to Huang-hu’s camp.

Several days after the bear misidentification incident, Huang-hu became able to gigantify to the size of a small elephant. A giant cat the size of a small elephant moving around with agility no different from an ordinary stray cat is basically a biological weapon. Huang-hu could probably crumple a car just by running into it.

Unlike Tai-yi, Huang-hu did not actively command his subordinate cats. He simply gave food to cats who came to him hungry, and when injured cats mewed weakly asking for help, he would hold them by the scruff and carry them to a safe sleeping place.
Big, strong, gives food, protects your safety—a reliable boss cat.

Though Huang-hu didn’t have the negotiation ability Tai-yi possessed, he had a natural talent for fighting using the gigantification ability. He fully unleashed the power he couldn’t exert in his harsh, emaciated, wounded condition.
Given the setting that Qitaohe City contains the World Shadow, I tried pitting Huang-hu against it once, and with his default agile body distracting it, then gigantification only at the moment of attack to deliver a cat punch that was a surprise kill, he annihilated it instantly.
Seriously strong. Cat-speed plus elephant-size power is no joke. The World Shadow was blown away in one hit, spilling the water inside it. With its default strength settings, the World Shadow stood no chance.

I also tried out the gigantification serum, refined by Baba from blood extracted from Huang-hu—but with the change in viewpoint height and limb length, it was nothing but discomfort. I nearly fell over several times just by walking for a few seconds.
Yet Huang-hu handled it with ease. What a creature.

Huang-hu’s growth was tremendously fast, and he was well within the practical combat range, so we decided to move into the event of cooperating to defeat the rampaging ability user.

Tai-yi’s ability growth had stopped and she was busily increasing her subordinates, while Haoran-kun had temporarily paused basic training and moved to applied training. He went to an amusement park, spun the teacups at full power together with Baba, and learned to reinterpret centrifugal sensation as gravitational sensation. Haoran-kun is now able to control the direction of gravity affecting himself.
Meaning he can fall upward or fall sideways, but fine control is still difficult, and he can’t yet activate it reflexively or adjust gravitational load. Once he learns to do that, the number of things he can do will increase and he’ll become unmanageable, so entering the event now was advisable, according to Baba.

After coordinating with Baba, I set the rampage of the evil power within me for three days later, and decided to do the final preparations before the event.
At dusk, sitting on the outdoor unit with Huang-hu curled up on my lap, I began speaking. Around us, about a dozen stray cats were hanging around. They came and went, communicating with each other, begging for food, or simply relaxing. The faces changed depending on the time of day, so I couldn’t grasp the total number, but it was estimated to be close to a hundred.

“Huang-hu.”
“Mew (Hm)?”

When I called to him while stroking his chin, Huang-hu, who had been purring, answered in a slack voice.

“We’ve gotten a lot of friends lately, haven’t we?”
“Meow (We sure do).”
“There’s something we need to do. It will be a harsh and agonizing trial, Huang-hu. You’ll have to endure pain. But it is something you need to accept. For the sake of our happy future, you must absolutely endure it. Will you do it? Do you think you can endure it?”
“Mew… Meow meow, mew mrrow (I don’t know what it is… But if I must endure it, then endure it I will).”

Huang-hu nodded bravely, full of complete trust, determination, and resolve.
There was pride in him. He had the confidence of one who had survived the harsh and severe winters alone.
So dang cool. Was it unnecessary to even ask about his resolve? When it comes to endurance, there is probably no cat in the whole of China that surpasses Huang-hu.
With relief, I asked.

“Let’s get vaccinations.”
“Mrrooow… (Vaccinations…)?

Yes.
Feline viral rhinotracheitis, feline calicivirus infection, feline panleukopenia, feline chlamydia infection, feline leukemia virus infection, feline immunodeficiency virus infection, rabies. Vaccinations against these seven infectious diseases will absolutely be necessary.
Leaving aside the majority of the healthy house-cat coalition, who are mostly vaccinated, if stray cats in poor sanitary and nutritional conditions band together, diseases will spread rapidly and a pandemic will occur.
Vaccination is essential.

“In other words, injections. A needle goes ‘prick’ into your skin and the medicine— Ah, don’t run! Bad boy! Wait! Wait, Huang-hu! Damn it!”

Huang-hu fled with his tail tucked. The other stray cats, who didn’t understand what injections were, panicked and scattered when they saw their daring and resolute boss cat fleeing in abject terror.

I spent the time until the next morning capturing cats and giving vaccinations, buying the resentment of stray cats who were forcibly given a prick as their reward and were in shock.
I’m really sorry, but it’s necessary. Forgive me.