Yoruichi nodded, "Yes, there is something I need Captain Ailin's assistance with."
Even though Ailin had married into the Kuchiki family and become their son-in-law, his displayed strength made all the other Captains and even the members of the 6th division recognize that he had the capability to be a Captain.
So everyone addressed Ailin as "Captain Ailin" instead of "Captain Kuchiki". This represented that the one they acknowledged as the Captain of the 6th division was Ailin the person, not his Kuchiki family status.
This was completely different from Ailin's memory of Kōga Kuchiki's situation. Ailin remembered that in his memories, the reason Kōga Kuchiki eventually rebelled was because before joining the 6th division, he had not displayed powerful strength in front of the division members, leaving them with the impression of him being more of a "Kuchiki family son-in-law".
So later when he gradually revealed his strength and made more contributions, eventually getting promoted to Vice Captain, everyone had already gotten used to his identity as the "Kuchiki family son-in-law". And this suppressed Kōga's pride.
When he was framed by nobles who secretly coveted the Kuchiki family, Kōga finally erupted. He directly broke out of prison to kill the nobles who framed him. In the end, his personality changed greatly as he slaughtered large numbers of Shinigamis, falling to become a traitor of Soul Society. He was eventually sealed away by Ginrei Kuchiki and Captain Commander Genryūsai Shigekuni Yamamoto.
"Ah, this mission is a bit troublesome, so I would like to ask Captain Ailin to work together to complete it."
Seeing Yoruichi and Ailin start discussing work matters, Ginrei Kuchiki pulled Byakuya Kuchiki away to not disturb their discussion.
"Oh?" Ailin raised an eyebrow in interest. Just what kind of mission was it that even made Yoruichi feel it was troublesome?
"Lady Yoruichi, please tell me first what kind of mission is it?"
"Mm, yes, I'll explain it to you first then," Yoruichi nodded, crossing her arms as she leaned against the cherry blossom tree.
"Over nine hundred years ago, aside from Soul Society, there was another force in this world that killed Hollows from Hueco Mundo entering the living world to hunt humans, protecting mankind. That force was called the 'Empire of Light'."
"The warriors of the Empire of Light were called 'Quincies'."
"Due to differences in ideology, over nine hundred years ago, the 1st generation 13 Court Guard Squads led by Captain Commander Yamamoto waged a great battle against the Empire of Light's Quincies, eventually successfully exterminating them."
Ailin nodded. He still knew this history. In fact, he possibly knew even more than what Yoruichi knew. He even knew that before the great battle against the 13 Court Guard Squads, the Quincy Emperor Yhwach of the Empire of Light's Wandenreich had negotiated with Ichibē Hyōsube, the commander of the Royal Guard protecting the Soul King Palace. In the end, Ichibē used the Soul King's right hand to seal Yhwach's special eyes ability.
"Over the close to a millennium since, Soul Society has been searching for Quincy remnants, wanting to completely purge the Quincy bloodline."
"Not long ago, the intelligence unit of the 8th Division collected the hideout location of some remaining Quincies in the living world. Captain Commander Yamamoto personally ordered for the 2nd Division and 13th Division to go to the living world together and exterminate these Quincy remnants."
"Wait..." Hearing Yoruichi speak to this point, Ailin couldn't help but raise a hand to interrupt her. "Lady Yoruichi, are these Quincy remnants really that powerful? You and Captain Ukitake have to personally take action yet still feel it's troublesome?"
Ailin wasn't certain just how powerful the current Yoruichi was. But she definitely wasn't as strong as two hundred years later after developing techniques like Shunkō and Beast Transformation.
But Jūshirō Ukitake, that old geezer Yamamoto's esteemed disciple, the Right Hand of the Soul King, was currently at his peak state. Among the current Captains of the 13 Court Guard Squads, his strength could rank in the top five.
Aside from Captain Commander Yamamoto, Shunsui Kyōraku, Sōya Kenpachi, and Retsu Unohana, the other Captains truly weren't much compared to Jūshirō Ukitake. Even 12th Division Captain Kirio Hikifune before her later promotion to the Royal Guard for her Spirit-Body Fusion technique shouldn't be Jūshirō Ukitake's match.
Of course, because he sacrificed one of his lungs, Jūshirō Ukitake would occasionally suffer great drops in strength from his illness, but even with greatly reduced strength, Jūshirō Ukitake was still above most other Captains.
From what Ailin knew, the truly powerful Quincies of the Empire of Light were all dragged by Yhwach's other half, the Soul King's left arm, into the shadows of Soul Society after their defeat by the 13 Court Guard Squads to hide away.
The Empire of Light had also become the unseen empire from that day forth, also called the "Hidden Empire"!
"Mm..." Questioned by Ailin like that, Yoruichi uncharacteristically fell silent.
As the family head of one of the Four Great Noble Families, no, as the family head of the Shihōin family among the Four Great Noble Families, Yoruichi knew exactly how her "Great Noble" status came about.
It was betrayal!
In the extremely distant past, there was originally only a single world, the "Living World".
At that time, the living world was filled with meaningless life and death. There was no progress nor regression. Even becoming a Hollow was part of the circulation process of souls.
However, as the "Hollows" transformed from the conversion of souls started devouring human souls, the souls that could reincarnate in this world became fewer and fewer. One day in the future, all the living world's souls would be completely devoured by a massive Hollow, becoming an enormous Hollow itself, plunging the world into stagnation.
At this time, the world gave birth to the "Soul King". Borne of the world itself, the "Soul King" possessed the "Almighty", the power over all creation. The Soul King converted his "Almighty" into the "Power of Destruction", using it to destroy the Hollows, lifting the crisis from the world as souls started reincarnating once more.
But while the world's crisis was resolved, those who witnessed the Soul King's power were unsatisfied with such a world.
Thus, the heads of the Five Great Noble Families, aside from the Shiba family, attempted to persuade the Soul King to create separate worlds of life and death - the living world, Hueco Mundo, and Soul Society.
But in the midst of communicating with the Soul King, the Tsunayashiro Clan's head joined hands with the other three Great Families to attack the Soul King, sealing him away in a crystal prison.
It seemed like through his powers, the Soul King saw the future and chose not to resist the betrayal, sacrificing himself to the schemes of the three Great Families' heads as they stole his powers to divide the chaotic world into the three realms.
Even so, despite the Soul King giving up resistance, aside from the Shiba family, the other three families didn't feel assured. Fearing that one day the Soul King would want revenge, under a silent agreement among the three families, the Tsunayashiro Clan spent countless years carving out the Soul King's heart, cutting off his legs, severing both arms, slicing open his organs before taking them out from his body, stripping away his powers before casting him down to the Mortal World.