On the third day, Fujin stood facing 10 human-sized rocks on the training ground. His fingers were pointing at each of the rocks. At the same time, he fired 10 Wind Lasers from the tip of his fingers. Every laser hit the top of the rock it was aimed at.

Fujin stopped the attack and once again pointed his fingers at the 10 rocks. 10 Wind Lasers were fired once again. However, this time, they didn't hit the rocks at the same time. Instead, the fastest reached in around 0.25 seconds while the slowest hit the rock in 1 second. The rest Wind Lasers hit at some moment in between those ranges.

Fujin thought, 'Great. I can use 10 Wind Lasers comfortably now. Not only can I aim accurately, but I can also control the speed. This will allow me to shoot Vacuum Bullets at varying speeds at the same time. This will make predicting the path of my Vacuum Bullets and dodging them much more difficult. In this aspect, this new Vacuum Bullet jutsu will be superior. The attack will be just too difficult to predict.'

Fujin stopped pointing at the rocks and decided, 'This is enough training for shooting 10 lasers at the same time. I should move on to working on perfecting the aim with 10 Vacuum Bullets at the same time. I can already do it with one Vacuum Bullet. So this will just need some practice until I get a hang of the remaining 9 as well.'

Fujin continued his training. However, shooting 10 Vacuum Bullets assisted by a Wind Laser each was very exhaustive on his chakra. In addition, he also had a couple of clones training to increase the speed delivered by the Wind Laser and another couple of clones training to position the Vacuum Bullet at different positions inside the Wind Laser. So he had to take a meditation break after every hour!

While Fujin was training, Hiruzen was reading the reports in his office. His main focus was on the report sent by Renjiro. He analyzed the report and thought, 'As we analyzed Onoki doesn't seem to have any intentions of starting a war. I'll ask them to stay there for another couple of weeks. If Iwa doesn't make any move, they can pull back and leave around 100 ninjas on our border to take care of any emergencies.'

He wrote a message and handed the scroll to an Anbu ninja to deliver. He picked up another file and began reading. His eyes widened immediately. He thought, 'The rate of consumption of the Wind Crystals reduced? How? Did that greedy boy finally think about the good of the village? Or was the effect too little for him?'

Hiruzen immediately activated his crystal ball and searched for Fujin in Training Ground 23. On not finding him there, he turned his attention to the Training Rooms. After looking for a bit, he found Fujin meditating in the Fire Training room.

A relaxed look appeared on Hiruzen's face. He could feel a lot of pressure being lifted off his shoulders. It almost looked like he became younger by a few years! He sighed in relief and thought, 'His rate of absorbing energy from Fire Crystals is just a fraction when compared with the Wind Crystals. If he doesn't decide to switch back to Wind Crystals, I can finally rest easy.'

Had Hiruzen been an emotional person, he might have cried tears of joy! Fujin had given him quite a headache and he had to make a lot of efforts to ensure that Konoha didn't run out of Wind Crystals. However, his confidence in his ability to do that was waning every day Fujin visited the Wind Training rooms.

Despite the good news, Hiruzen couldn't help but pray, 'I hope his speed of absorbing energy from Fire Crystals doesn't increase like what happened with the Wind Crystals.'

Two days later, Fujin was sitting with his back against a tree while breathing heavily. He muttered, 'I need to find who made this soldier pill. And I need to ask that person to make a better one. Despite being so good, it still isn't sufficient for training non-stop. Needing to take a break after just 50 minutes is rather annoying. Regardless'

A smile appeared on Fujin's face. He muttered, "I have mastered shooting Vacuum Bullets from my fingers. That Iwa army will be decimated if they face off against me right now!"

Fujin looked around him. There were hundreds of rocks and walls that he had raised from the ground using Earth Release. Every single one of them was riddled with holes! Several trees for hundreds of meters had suffered the same fate. If someone was to walk onto that training ground, they would wonder what exactly was happening there!

Fujin thought, 'Though this jutsu is considered mastered, there is still a lot of scope for improvement. I have increased their speed to just above half the speed of the Vacuum Bullets I shoot from my mouth. This makes this my fastest attack behind Vacuum Cannon and Vacuum Bullets.

But I can still increase this speed further. And I still need to keep working on the multi-directional variant by adjusting the position of the Vacuum Bullet. And I also need to work on firing multiple rounds in quick succession.'

Fujin analyzed for a few minutes and decided, 'I was planning to move on to my other ideas. But, I'll spend another 5 days, when I eat the third soldier pill, to improve this jutsu and master the multi-directional variant. After that, the improvement will become very slow. It will improve as I use them and I can spend additional time on this after I retire.

In the week until then, I will begin practicing the forms of my next idea for Vacuum jutsu. Still, just like Wind Laser jutsu, this one can also be said to be quite different. I should give it another name. Hmm, what should I give?'

Fujin thought for a few seconds before deciding, 'I will just call it Vacuum Gatling jutsu as I fire multiple bullets at the same time and I intend on improving it further to fire several rounds within a second. That should make the jutsu similar to the Gatling gun from my previous world. Yeah, I'll go with that. No point in thinking much about it.'

Fujin wasn't very concerned with the names of his jutsus. He just thought of a basic one and stopped thinking about it. After meditating and recovering his chakra, Fujin continued his training.

He stopped when just 2 hours were left for the effect of the pills to end and began moving back to his home. En route, he couldn't help but sigh and think, 'The Four Symbols Seal is still not mastered! And the constant influx of memories from those clones gives me such an intense headache! Processing a year's worth of memories in just 5 days repeatedly is a tough job. Especially when I am also training Ninjutsu.'

Fujin sighed again and muttered, "Oh well. I am almost done. I am very close now. My clones have succeeded in creating all parts of this seal. It's just that no one managed to make the entire seal by himself. Probably 2 more days of this torture and I will have this seal down. 3 at max if my luck is bad.'

Exhausted, Fujin took a couple of days off once again. During this time, he visited Isamu in Konoha's hospital to get his body checked and to heal any hidden injuries and eliminate the accumulated trauma. It helped Fujin in relieving the stress on his body and, to an extent, his mind.

After resting for a couple of days, Fujin returned to training once again. After completing the morning workout ritual and getting some rest, Fujin decided to work on adding more jutsus to his arsenal.

Fujin thought, 'This idea could be fun. Though Vacuum Gatling jutsu will be devastating, it'll be a shame if I have to expose it against normal Jounins. This jutsu can make their preparations useless while keeping my Vacuum Gatling to catch any rank S ninja off guard. Even if I'm not able to kill them, causing them a serious injury should be sufficient to force these villages to back off.'

Fujin raised his right hand and extended his index and middle finger towards the sky. His eyes focused on the two fingers as wind chakra began concentrating on the two fingers. A 15 cm long Vacuum core began forming on top of his two fingers. In a few seconds, the core took the form of a blade. It was soon enveloped by winds.

Fujin didn't move his fingers. Despite that, under his control, the blade flew towards a rock and cleanly sliced it into two!

A smile formed on Fujin's face. He muttered to himself, 'My compatibility with this jutsu is too good. Just like the Blade of Wind jutsu, I was able to succeed on its vacuum variant on my first try!'