After returning home, Feng Zheng thought, "This is probably the highest difficulty a Rank B mission can reach.
It seems my self-analysis of being Jonin-level was not wrong.
Unfortunately, Konoha will not promote me that quickly.
Furthermore, more challenging missions mean my life will face greater risks.
My calculations are correct.
I should use this time to strengthen myself as much as possible."
Feng Zheng walked into a room in the basement and turned on the light.
The room was empty.
Feng Zheng took out a scroll and summoned some equipment: a transformer, an ammeter, an ohmmeter, rubber boots, rubber gloves, and a few wires.
Feng Zheng put on his boots and began setting up the equipment, thinking, "To avoid suspicion, I've already memorized all five elemental training methods.
The Library only lacks training methods for the Yō Attribute and Yin Attribute.
Lightning Release training is relatively more complex than Wind Release and Earth Release, but still quite simple.
I just need to endure increasingly stronger shocks to master it."
"First, I need to measure my body's resistance.
Then, I need to use the transformer to subject my body to constantly increasing voltage.
This will generate an electric current in my body.
However, it must be done in stages.
My limbs can withstand higher currents.
But if the current passes through my heart or brain, it could be fatal.
These two parts must be trained separately."
"The first step to learning Lightning Release is to be able to withstand 10 amps of current flowing through the entire body for one minute.
The second step is to generate such a large current in the hands.
With just these two steps, I can learn Rank B Lightning Release Ninjutsu.
Rank A and Rank S Lightning Release Ninjutsu require me to be able to resist and generate stronger currents."
"In other words, increasing the current intensity I can generate can enhance lower-level Ninjutsu.
Of course, on the other hand, after being able to generate 100 milliamps of current, I can use Ninjutsu below Rank C.
But it won't be very strong."
Feng Zheng finished setting up, created a Shadow Clone to control the voltage, and set up two open wires.
Feng Zheng grabbed one with his left hand and tied the second wire to his upper arm.
This way, the current would enter his hand, pass through his arm, and then exit through the wire connected to his upper arm.
The Shadow Clone set the transformer's output to 10 volts and turned it on.
Current began to flow through Feng Zheng's body.
A number appeared on the ammeter connected to the circuit.
The reading was 0.125 milliamps.
Feng Zheng began to calculate in his mind.
"10 volts for 0.125 milliamps means my body's electrical resistance is 80,000 ohms.
The scroll said that when the current reaches 1 milliamp, I should be able to feel it."
He looked at his Shadow Clone and said, "Increase the voltage to 80 volts."
The Shadow Clone nodded and increased the transformer's output.
Immediately, Feng Zheng felt a slight tingling sensation in his arm.
Feng Zheng let the current flow through his arm for one minute.
Then he said to his clone, "Increase it to 200 volts."
His Shadow Clone continued to increase the voltage.
The current rose to 2.5 milliamps.
For Feng Zheng, there was still no pain.
Feng Zheng recalled the details on the scroll.
"The scroll is right, we feel the current at 1 milliamp.
For ordinary people, 5 milliamps is very uncomfortable but not very painful.
From 6 milliamps, pain begins to be felt.
From then on, muscles begin to lose control.
If an ordinary person is hit by this, he will involuntarily let go of the object that is electrifying him."
"Above 17 milliamps, ordinary people will begin to experience extreme pain.
He cannot let go of the object, and there is a possibility of death.
Above 100 milliamps, the heart's pumping becomes uncoordinated, and nerves begin to be damaged.
At 2 amps, there is a high probability of cardiac arrest, internal organ damage, and severe burns.
The probability of death is very high."
"However, as a Ninja whose body has been trained with Chakra, my endurance can be higher.
But this will still be very dangerous.
Once the pain starts, I must be very careful."
He added, "Increase the voltage to 400 volts."
The Shadow Clone increased the voltage and said, "Don't forget, after 500 volts, the body's resistance will suddenly drop."
Feng Zheng nodded and said, "Yes.
However, the drop in resistance is due to the destruction of the outer layer of the skin, and since I have trained, the resistance might be higher.
However, still pay attention to the ammeter; if the value suddenly increases and the current starts to rise, turn off the switch.
One or two seconds of high current will not be fatal.
Also, there is a fuse that will blow at 100 milliamps."
The Shadow Clone nodded.
Feng Zheng continued to slowly increase the voltage.
Half an hour later, the Shadow Clone raised the transformer's output to 4000 volts!
50 milliamps of current flowed through Feng Zheng's arm.
Feng Zheng thought, "I can finally feel the pain!
It seems my tolerance for electricity is about 8 to 10 times higher than that of an ordinary person."
He took some time to adapt to the pain.
Once the pain subsided, he increased the voltage again.
At 5000 volts, the ammeter read 62.5 milliamps.
However, the pain suddenly increased rapidly!
The Shadow Clone immediately turned off the switch.
Feng Zheng let go of the wire and removed the one connected to him.
He shook his arm and said, "It hurts so much!"
The Shadow Clone laughed, "Reaching 62.5 milliamps in less than an hour is already a huge improvement."
However, Feng Zheng shook his head and said, "This is just the endurance I've naturally developed over the years; from now on, the main training begins.
I have a premonition that it will take a long time to reach the necessary endurance."
He thought, "I wonder how Sasuke learned Lightning Release and mastered Chidori in less than a month.
Was it just his talent and Sharingan?
Or Kakashi, no, could it be that the Hatake clan has better methods to master Lightning Release?"
Feng Zheng repeated the same training on his remaining three limbs.
Subsequently, he let the current flow through his chest by having it flow from one hand to the other.
He started with low current and stopped at 5 milliamps.
He repeated the same action, and after taking off his shoes, he let the current flow from the top of his head to the ground.
Feng Zheng trained like this for a week.
By this time, his limbs could withstand 500 milliamps of current, and his entire body could withstand 100 milliamps.
He could also generate 250 milliamps of current in his hands.
During these seven days, to avoid suspicion, he also went to the Training Grounds every morning and after lunch to exercise and practice Wind Release Ninjutsu and Wind Vacuum Technique for several hours.
The Lightning Release training also had a great impact on Feng Zheng's physique.
Feng Zheng noticed, "Besides learning Lightning Release, this method has also had a great effect on my body.
I can feel my body becoming slightly stronger due to those electric shocks.
However, it should become ineffective after some time.
Just like Senju Taijutsu increased my Chakra.
However, this physical enhancement is still very helpful."
For the next few months, Feng Zheng focused on cultivating the Lightning Release.
The Lightning Release training combined with the high-intensity morning exercises had a very significant effect on his body; he could now exercise at 95% Sealing Jutsu pressure.
During this period, he completed seven Rank B missions with his team.
Seeing his abilities, Feng Zheng played a more important role in the team.
However, these missions were not very challenging.
Eventually, Feng Zheng successfully generated 10 amps of current.
When the ammeter showed 10 amps, he and his Shadow Clone both smiled happily.
Feng Zheng said, "Now it's time to learn Lightning Release Ninjutsu; you go to the Library.
Look up Ninjutsu for Lightning, Fire, and Water Release."
The Shadow Clone nodded and left.
Feng Zheng meditated in the Meditation Room until the Shadow Clone sent back the information.
The Shadow Clone began to review all Fire Release, Lightning Release, and Water Release Ninjutsu from Zones E, D, C, and B.
Of course, he only focused on reading Lightning Release Ninjutsu.
As for the Fire Release and Water Release scrolls, the Shadow Clone pretended to read them while analyzing the Lightning Release Ninjutsu he was reading.
A few hours later, the Shadow Clone dispelled itself, transmitting the information back!