Shinigami ways
Ichibe Hyosube decided to talk to other guards regarding Leo's situation, Soul King orders were very clear, they all were meant to train Leo in everything but the problem was that no one knew about this origin or what the energy wave which Leo emitted was.
At this moment Royal guard senior level only consisted of 4 members with 2 others in consideration. Kirio Hikifune with her recent work on the artificial soul has brought the attention of Soul king onto herself but the research was still incomplete thus her initiation was also not full. She was allowed to work in the Royal Place of Soul King but didn't have much freedom. Another member was Senjumaru Shutara, she developed a method via which non-living things such as Skeleton of a person can be reused as a mean of offense and defense depending on the power an individual had. The non-living thing can be used as a foot soldier or perhaps a helping hand in a fight, all the capacity were unknown regarding the technique which is why she wasn't completely integrated into the soul king's royal guard.
Ichibe took Leo who was pretending to have lost all his memories which usually happen to a soul when they cross the boundary of living and the dead thus Ichibe just called him Kiddo, for now, he took Leo to see Oetsu Nimaiya, Tenjo Kirinji and Renjiro Kimura the other 3 top members of the Royal guards. Oetsu Nimaiya was regarded as the King of the swords as he was the creator of all the Zanpakato, he forged all which existed and also knew the locations of all Zanpakato spirits. Renjiro Kirinji was regarded for his invention of the White bone hell - a sprit water pool that removed all the blood from an individual which was tainted by foreign Reiatsu, fastening the process of healing then came his second invention blood pool hell where an individual who has lost his blood will regain blood thus not weakening them for a longer period and reducing their recovery time. The last member was an only bit younger than Ichibe himself, him the original manga series which Leo had knowledge of the character simply didn't exist, he held the title of Space wave as his powers were deemed to be special by the soul society when it was formed and he was made part of the royal guard following this. His power was such that he could redirect or transfer the position of anyone with himself thus changing the course of attack which was about to hit him onto someone else.
Ichibe brought the boy in his place whereas sent orders to all three to come there.
Leo stood in front of 4 people while they stared at every inch of his body trying to understand everything about him seeing this Leo laughed and stared giving them gestures. Ichibe broke the silence stating the order of the Soul king to teach Leo here. Oetsu laziest of the bunch said he is very right now and won't be able to help and ran away but Tenjiro caught him and brought him back.
Ichibe instructed Leo to go outside and wait for them. Leo simply smiled and left, Ichibe started talking stating that he will start teaching the boy first to learn more about him. Boy would be allowed to stay within the Soul Palace for now and monitored. No news regarding the boy must be leaked to the outside world.
Leo in the meanwhile started testing his body, he first absorbed his black coin from the harry potter world. Second, he started testing Haki and his energy. About his energy and Haki depended on his will power so he went into meditative position and found he had very little control over either. Then he started checking Hope to see the damage which has happened to it during the tribunal. Hope reported that connection with World seed has been broken, the sealed consciousness of the people which were uploaded was erased and most likely sent back in time as if nothing ever happened. Kurama dimension is also sealed off and the host needs to revisit the naruto world to reconnect with the power. The machines left behind in One piece are still there, the timeline of that world wasn't erased only his forces which re-uploaded into the world seed when the tribunal hit Leo. The rest of the timeline of the world was erased to the point when Leo first entered the world. All the information which was collected during his travel was also available.
Leo started formulating new plans for each world, The last time he was in the world all he did was collect information and focused on the tasks this time he will start building the empire. For future battles, he will need soldiers now that Asuna is alive and waiting for him he will destroy all gods if that's what it takes. With plan set in his mind. Leo waited for the Royal guards to be done with their talk.
Soon Ichibe and others came out of the room and told Leo that he, for now, will be staying with Ichibe start learning from him.
The monk who calls the real name was anything but kind in any manner, he was focused and wanted to draw out every little bit of information and power Leo had, the training begins with the theory parts of Reiatsu, the formation, usage, and most importantly control. Little by little with Leo started formulation his understanding of his bodily energy. His body consisted of different kinds of energies with Reiatsu only being a part of it thus not all boundaries applied to it. Leo with his understanding controlled his energy and didn't let it omit any longer making him seem like a normal mortal. He started using the energy in different forms such as forming wings swords and others. Ichibe observed all this and classified that Leo was a once in a lifetime genius.
Leo was named by Ichibe as Keiko from Kiddo. Within 10 years, Leo/Keiko learned all the theories from Ichibe, then begin his learning toward Zankensoki basic techniques, Ichibe being the oldest and most experienced taught him, Kido, Senjumaru who specialized in Hakuda was assigned to teach him that, Tenjiro whose renowned as "Lightning-Fast Tenjirō" was assigned to teach him Hoho, Oetsu Nimariya started teaching him basic Zanjutsu using wooden swords along with Ichibe. Renjiro started teaching Leo Hakuda, different methods to fight without a sword use, via arm surrounding and lastly space.
Kirio was assigned to teach Keiko about the technological part of the soul society and it's working basics started with Jigokucho which were used by the shinigami's to travel from one plan to another from the world of soul society to the world of the living, and were also used as messengers in Soul society. Keiko was very interested in the technological aspects and using his understanding started paying more interest in Kirio work, who upon see Keiko's mind and his brilliance was more than happy to teach him more, with the help of Keiko things such as Spiritual limiters were also improved giving more stability to the powers which were steeled and producing less stress on to the Shinigan's body.
Keiko also helped in the development of a new kind of Denreishink which came with an inbuild hollow graphic future which can be used to scout out the area first and identify hallows and their kind and strength thus decreasing the deaths of shinigami during a battle between the two. Keiko maintained a good relationship with everyone, with not getting attached to anyone but at the same time being on a close relationship with everyone.
With the teaching and contributions made by Keiko in developing various new technology, Keiko was officially integrated into the royal guards under the division of Tenjiro Kirinji. With the integration, Keiko finally received the key to the royal place and finally the freedom to travel anywhere he wanted. Oetsu Nimaiya from time to time forged new Zanpakuto, Keiko from the side only observed the process of creation, Oetsu offered to create one of Keiko, but any swords Oetsu forged crumbled into ashes when Keiko touch it confusion both of them thus after thinking it over Keiko decided on learning how to create one on his own. Oetus with his close relationship with Keiko after gaining permission from Ichibe started teaching Keiko how to forge a Zanpakuto. Little by little is the understanding of forging improved. Keiko using Hope started accumulating the knowledge of one piece Wano country spirit and his world's spirits, running various calculations and such.
As Keiko learned everything 400 years went by Senjumara become the leader of the first division with Royal guards with control over her unit of royal soldiers. And after 50 or so years Kirio also succeeded in her research and created Artificial souls theory by the name of Gikon along with the Cage of life defense technique which absorbed all Reiatsu based attacks.
Keiko with practice become a master Shunpo master being able to even be faster than his master Tenjiro, he also inherited the complete legacy of Renjiro regarding space manipulation and control. World laws did not apply to Keiko as they were on Renjiro thus making it easier and fluid for Keiko to do as he pleased. Keiko's title was finally decided by Ichibe as the Swordless titan because even with the use of Zanpakuto, Keiko using speed and space as a medium was able to keep up with any one of the royal guards. Fighting them on the equal ground regardless of the opponent using their bankai or any other technique
With everything learned about the soul society world of Shinigami, Leo decided to visit Hollow world, the Hueco Mundo was a world full of white sand and nothing more, Keiko was interested in the formation of Hogyoku, the likes of Sosuke Aizen and Kisuke Urahara were able to create one, thus he was also somewhat confident he will be able to form one like them, Keiko collected various kinds of Hollows one at a time while leaving the 3 so-called kings not wanting to interfere with the timeline of Ichigo and his adventures, with thousand of hollows it was easier for Keiko to get experimental subjects.
With discussion to Kirio and Ichibe, a specialized branch was created inside the royal guard unit to study Hollows separate from the soul society one. Keiko alone worked on the Hollows and started his expriments, his first conclusion was correct, the gods have made his body in the same manner as that of Ichigo which consisted of both kind of energy, but it was also a very small part of his total energy thus Keiko begins suspecting that he also have Quincy power too. Leaving that thought, for now, Keiko started learning hollow and about Hollowfication. Little by little learning about hollows their powers and techniques such as moment technique Sonido which equally powerful to Shinigami Shunpo, Acidic Touch an offensive attack via which Hollow's Reiatsu to seep into the person causing great pain to the victim with great control can also be used against Shinigami, Cero offensive swift energy blast technique and lastly their travel technique Garganta tearing the fabrics of the space itself thus creating a medium of pathway between worlds.