To create a workable plan, Fujin had one clone in the library the entire time that he wasn't on missions. His clone looked through the entire library to find any methods and seals to help him find a way to infiltrate the Uchiha compound.
After researching and practicing for a month, Fujin had found all the means to create a plan and try his luck while ensuring his safety and anonymity. He began the preparations.
While Fujin was making his preparations, the Uchiha clan too began their preparations. All active Uchiha ninjas were called back. Every single Uchiha ninja returned back to Konoha. They began to prepare themselves for the war.
Meanwhile, Danzo met Itachi in secret and explained to him what would happen when the Uchiha revolted, once again. He convinced Itachi to take action against his own clan.
However, while the two were talking, their actions were seen by one person. In his room, Hiruzen watched their whole interaction in his crystal ball. Surprisingly, neither Danzo nor Itachi sensed anything off.
Tiredness could be seen on Hiruzen's face as he sighed on seeing his friend's actions, 'I would have stopped him. Unfortunately, the relationship between the village and the Uchiha clan has deteriorated beyond repair.'
His expression became firm as he decided not to interfere, 'While it's true that they were relocated to the outskirts of the village and monitored by Anbu, no Uchiha was ever mistreated by us. I can understand that they would be dissatisfied with such a treatment. However, this is no excuse for launching a coup that would destroy the village.'
On deciding the fate of the Uchiha, Hiruzen's eyes fell on Danzo, 'My old friend, it looks like you have completely fallen into Darkness. This will be the last time you will interfere in the matters of my village.'
While the undercurrents were flowing in Konoha, Fujin was busy in his basement making a lot of complicated seals. A day after Mieko told him the news, Fujin completed the first step of his plan.
He took a deep breath, 'Finally, it's done!'
He made a hand sign. A shadow clone appeared next to him. The clone made multiple hand signs. Fujin observed the clone by concentrating chakra in his eyes. He could see that the chakra signature of the clone was slowly changing. Soon, it was very different from Fujin's chakra signature. His scent also changed.
The honey badger clones would roam around Konoha all night and disperse themselves when the Sun rose. Fujin experimented for two days before deciding that they were safe to be used. From the 3rd day, all 6 of his honey badger clones used to stay around the Uchiha clan compound. In addition, Fujin would maintain 2 wind clones at one secluded spot a few kilometers from the Uchiha clan compound.
With the preparations done, Fujin just waited for the right moment.
A few days later, in an underground base under Konoha, Danzo stood with a subordinate. The subordinate respectfully asked, "What job do you have for me, Danzo-sama?"
Danzo looked at him and said, "Your Triatominae bugs can induce sluggishness, right?"
The Root ninja was from the Aburame clan. He replied, "Yes Danzo-sama. They can cause slight sluggishness with their poison. And since it poses no direct threat and doesn't have any color or smell, it is almost impossible to detect."
Danzo said, "Good. Your mission is to poison the drinking water that reaches the Uchiha clan with this poison. Use very small quantities. Your main priority is that this poison isn't noticed. Once you are done, go to training ground 49 and wait for me."
The Root ninja was surprised by the mission. However, it wasn't his place to question Danzo. He nodded and left. Danzo watched him leave as he thought, 'He was a good subordinate. A shame that he has to die.'
Danzo called another subordinate of his and instructed him to approach the Aburame ninja in the training ground 49 and kill him and dispose of his body as well. Though Danzo's subordinates had his curse seal, no seal was perfect. Considering the importance and severity of this matter, Danzo decided to take this step. This way no one other than him and the elders would know about the truth of the Uchiha massacre.
The Root ninja from the Aburame clan did his job exceptionally well. Since it only caused a slight sluggishness, no Uchiha ninja realized that they had been drugged. After all, they didn't have to move at full speed in their normal lives.
Danzo made a few more moves that day. He ensured that no Hyuga, Inuzuka or Sensor ninja was in the vicinity of the Uchiha clan compound to prevent any interference. In fact, he had ensured that most of their active ninjas were on duty outside Konoha.
Finally, on that evening, Uchiha Itachi and Uchiha Obito appeared in the Uchiha clan compound. Almost everyone in the village was oblivious to the massacre that was about to unfold. Only 3 were aware of it and waited patiently.
Danzo was busy with his Root ninjas to ensure that Itachi wasn't interrupted. Meanwhile, he also had to ensure that his Root ninjas weren't close to the Uchiha clan compound and get caught in the fighting. Hiruzen had recalled all Anbu ninjas that were keeping an eye on the Uchiha clan. While Fujin was waiting in his basement for his clones to send him a message.