Hollow's howl

Hollow's were a very unique subject for Keiko who first started understanding their powers and then their pain endurability before they are harmed, he started practicing different methods via which a Hollow can be destroyed. What Shinigami did with their swords was purify the darkness within hollow's and convert them into the soul which were then reincarnated in soul society as soul and later either as humans or shinigami if they were found to contain a high level of Reiatsu.

Keiko was very fascinated by them how their lost heart converts into their mask giving them a specialized appearance of sort within the Hollow class itself.

Using various method Keiko identified a method by which a hollow's very soul can be extracted from their being while destroying their very Reiatsu network thus giving Keiko the very precious soul which according to what he has heard can give power to lesser gods, using this model, Keiko started his experiments on how to gain control over the very soul of this kind thus making them his indirect servents.

With years of research and using the theory of Gikon which Kirio Hikifune had developed as an argument bases, Keiko developed his theory of Hollow soul and how to control them directly. The method was such that which containing his Reiatsu which had Hollow energy directly into the Hollow's very soul without destroying the Hollow's Reiatsu network which formed the body of a hollow. Using Hope to do the calculation, Keiko was finally able to control over Hollows which were of lower Reiatsu level them him.

Around 420 years had passed by since Keiko coming the Royal guard unit, trained under everyone, and finally, become part of it. In the beginning, he was placed under the division of Tenjiro Kirinji unit but was later placed under Kirio Hikifune because of his interest and contributions to developing various items. Keiko was given his own King's key which only given to the Royal Guards who were at most trusted. 420 years later he had both Shinigami and Hollow's fighting techniques with addition to Hollow under control to behave and follow his command. During this time Keiko also started practicing his Reiatsu regulation technique which he created using both Shinigami and hollow as an example while also practicing Haki. By the end of 420 years, he had achieved light golden Haki or which Keiko named as God's Haki using IM as an example.

With Hollow's under his control, Keiko started his next research, Hogyoku for which he needed Shinigami. Using Hollow's under his control he attacked the nearby parameter of the soul society which was a regular thing for Hollow's to do. Soul society seeing this dispatched their division 2 members who specialized in speedy execution. The captain leading them was Sui Feng. Keiko gathered around 200 Hollows to attack but after observing that it was Sui Feng's unit, Keiko decided to take part in the capture himself too. The attack started as usual but unlike usual Hollow's didn't kill the injured Shinigami's but took them back with them, Keiko collected everyone within his dimension. After destroying the first wave of enemies and collecting about 15 people, Keiko retrieved. Leaving some Hollow behind making it less suspicious and giving a target to upcoming shinigami to kill and blam.

15 people he took were brought back into Hueco Mundo, by this time Aizen had already outed Kirsuke Urahara and others as part of the blame for Hollowfication and started his plans into the Hueco Mundo itself. Keiko using his Hollow's also infiltrated into his gang while observing his moves. He created an underground research center for himself where he could play with Shinigami as if he did this in soul king's place he would have to answer to Orihine and others which he wanted to avoid for now. He started with understanding their soul formation, basically how the souls were classified as good and bad into Hueco Mundo and Soul society.

It took about 20 years into the soul when Keiko finally had the understanding and the means to manipulate a soul into transforming from one into another. What Aizen and Urahara did while forming the Hogyoku was just try to merge the power of the two without understanding the base of the two and the reason thus creating an unperfect Hogyoku which had a consciousness of its own while not being under their control.

Keiko's approach yields him different results while giving him perfect control. Soul used as a means to fuel increase the power of a Hogyoku by which it could change the reality itself thus giving it god likeability which made Aizen crazy believing it to God's true power which he will gain if he merges with the Hogyoku.

Keiko using different Hollow's and Shinigami which he started capturing started fueling different Hogyoku with different Output. He also started with the experiments on how to merge the two without letting it form a consciousness of its own.

Meanwhile, in the outer world, Aizen started experimenting with his own Hogyoku and realized that the power outlet of his Hogyoku had started decreasing thus tried to feed it by using different methods such as killing residents of the villages nearby, Hollows which he captured and the Shinigami's he lured but the power still didn't increase or was regained by his Hogyoku thus he decides on two plans first to merge the Hogyoku which Urahara had created. The second was to involve the individual known as Swordless titan who was famous for being one upon a lifetime genius who was rumored to have helped Kirio Hikifune in her theory of Gakai. Usually, no one can control the royal guards or their selection and duties but the rumored Swordless titan was different, he was said to have been grown up with the soul palace under the watch of Royal guards but was not one of them fully but working under them thus, using Central 46 he could make the individual in question a suspect of the disappearing Shinigamis and bring him to soul society under the pretense of keeping him under observation. He could influence the individual into working for him. After some thinking,

he decided to enact both his plans, thinking if that if anything went wrong he could always use the center 46 to send back the Soul palace or depend on Rogyoku.

But a problem arose in his second plan, no one has ever seen what the Swordless titan looks like, about 400 years had passed since he had been in Royal palace which Aizen didn't have any connections with. After some thinking, Aizen using other captains into a rush that had connections with the Royal family started collecting information about Swordless Titan.

And finally got a photo, A man wearing completely white from head to toe, with both arms behind him, eyes of blue color with an expressionless Handsome face, body towering around 6'4 in height a lean muscular body, completely white-colored short hair as if he had just gotten out of bed looking directly into the camera with a small smile on his face.

Aizen who was very confident his looks was also impressed. He used this as an example started creating illusions around the areas where Shinigami go missing people seeing someone like Keiko. Soon a photo of Keiko was made using various eyewitnesses, the person who Aizen had manipulated into getting the photo had already seen the photo and thus identified Keiko intently. Thus, starting the conflict of power with Center 46 and the royal palace who were certain that Keiko wasn't in any manner involved specially Ichibe. Keiko was also instructed to come back out in the open to discuss the event.

When Ichibie asked Keiko about his involvement and informed him regarding the whole matter, Keiko instantly knew he was dragged into a trap by someone. Keiko denied any involvement in the matter. Ichibie also informed him about the decision which Center 46 had decided. To have him serve as a Lieutenant under a captain of Gotei 13 the entire matter is clear. Keiko hearing just smiled and agreed.