Ryuzaki was sitting inside his house in meditation with his sword in his lap when suddenly he heard the sound of people shouting and fighting. < Looks like Itachi started, then I should start also.>
He raised his palm facing up as he manipulated his reiryoku. The the souls of the dying people started to gather around him and started to condense in a orb upon his palm. The orb was murky like a black ball but it was beginning to clear as more souls gathered in the ball.
Outside the sound of fighting got closer and closer to his house. His house was in the furthest corner so he didn't have to fight right away. Seeing the souls Ryuzaki felt some kind of excitement in his soul. < It looks like Hollow power is acting up. It haven't tasted a soul ever before but the instinct of a Hollow is still there.
Suddenly through the window came Obito crashing down. " Oohh....What is this?? Are you trying to do some kind of a jutsu."
"Yes I am but it is not meant for you, it is for my usage." Ryuzaki said staring at Obito.
"If this is not to attack me then how are going to save your life. You should have heard the sound of fighting and peoples dying scream. You should start preparing to fight as this is Uchiha massacre." Obito said slightly laughing. He got some time to play around as this is the last house. And through his sharingan he saw there was only this kid and that this kid also don't have any chakra made this job much easier making him relaxed.
"Even if this a Uchiha massacre there is nothing for me to do. And as for attacking you it doesn't matter, if I want to kill you then even god will not be able to save you from me." replied Ryuzaki still sitting and holding the ball in his hand. There is more soul coming as Itachi is still killing people.
Hearing the arrogant word Obito didn't know what to say as he looked stumped. "So much confident for a crippled who cannot use chakra. It is good to be confident but to be so arrogant is not good." saying so he sat down in front of Ryuzaki but didn't attack him as he wanted to know what he is preparing with that ball.
As Obito is not a shinigami he cannot see the souls gathering he can only see that the orb is which is black in colour is getting more clearer. And Ryuzaki is not attacking him as he is waiting for the orb to be completed as he doesn't want to repeat the same thing because if he let go of the orb then he would have to start from scratch.
Even if Obito attack him it will make not much of a difference as long as he doesn't let the orb go. So when he saw Obito sitting he didn't say anything.
"Hey, I am curious about that orb your holding. What is that?" Obito asked as he can feel some type of soothing sensation coming from the orb but doesn't know what it is.
"It is made of souls which is concentrated to become pure energy which will make my soul strong. As this soul is pure without any blemishes it contained power and their knowledge without any lingering feelings." Ryuzaki said in a somewhat excited voice. Ryuzaki was doing what cultivation world do and that is refining energy. To attract a soul he needed to have the power of Fullbringer who can control souls.
Shinigami cannot control souls as they are law bound. They can only purify souls and with the help of Fullbringer he can control the souls. And the Hollow power is to eat so there is no use in it for now, and Quincy is to kill even more so no use in it.
Listening to Ryuzaki saying that orb is made of souls Obito was startled as he suddenly got up and took a defensive posture. As collecting souls is not a casual matter, as far as he knew there are only handful of justsu which dwell on souls and they are dangerous.
Looking at the defensive posture of Obito, Ryuzaki said "Don't worry I cannot take a soul without killing someone. I am not that capable of doing that kind of thing right now at least." Ryuzaki smiled a little at the end of his sentence.
Hearing what he said Obito became weary of him and said " Looks like the most dangerous one in the clan was residing here and we actually kept this one for last." saying he immediately threw shurikens at Ryuzaki and took out a kunai rushing at him.
Swiping with his sheathed sword at the shurikens Ryuzaki used Utsusemi to dodge the attack leaving an afterimage standing outside of his house. Seeing that he hit an afterimage Obito looked at Ryuzaki who was standing outside.
When Ryuzaki saw that there is no more soul coming, he knew that last Uchiha is dead. "Bakudo #4 : Hainawa " a rope made of reishi wrapped around Obito as Ryuzaki used Shunpo to get away to integrate the orb. Seeing the rope bind him Obito used kamui to get from the bind.
Obito started thinking what kind of jutsu was this as he didn't give chase to Ryuzaki. To begin with he don't know where he is gone to, Ryuzaki moved to fast for even his sharingan to see as he was dealing with the yellow rope.
Getting away from Obito, Ryuzaki stood inside the house of someone else. Didn't minding the corpse inside the house Ryuzaki sat down and started to focus. He saw the orb become the size of a basketball as he used his reiroku to condense the ball into the size of a tennis ball. The more he condensed the more the ball become smaller and translucent.
After five minutes, there laid in his hand a orb the size of a tennis ball and translucent like a marble. He directly ate the orb and integrated it with his soul. His soul become somewhat translucent with the power of orb becoming pure but not much, as he needed more souls to do that.
But with this amount of souls his soul become more stronger and purer. He also got the memories of the soul and the power of Uchiha bloodline Eternal Mangekyou Sharingan. Before he only had the body of Uchiha and bloodline but because he don't use chakra he could not awaken Eternal Mangekyou Sharingan. Even if he did awaken Sharingan somehow it will be a defective one like normal one where they had to transplant eyes to achieve EMS. But with this much souls his soul got stronger and bloodline become purer but not by much.
EMS is not something you can simply gain by eyes, it is something that is integrated with their soul. If not then Danzo could have gotten a Mangekyou Sharingan because of transplant. As for Kakashi getting Mangekyou Sharingan, its not his power that awakened it. It was Obito who achieved it and Kakashi got the other as side effect.
With this Ryuzaki's first step is completed now and the other step had to wait until the fourth ninja war.