Kisuke sighed helplessly. "Yare yare, what can I do? Fine, since you don't understand, I won't waste my breath. In short, you just need to know that to prevent Soul Suicide, save Kurosaki Masaki's life, prevent her Hollowfication, and maintain her humanity, it requires powerful power..."
"...The powerful power of a Shinigami!"
"And this power needs to stay by Ms. Kurosaki's side, inseparable until her death, suppressing her Hollowfication." Kisuke gave up explaining and directly stated the outcome.
Hearing this, Ryuken immediately roared, "That's nonsense!!"
"There must... there must be another way...!" Ryuken said, looking at Kisuke unwillingly.
Ryuken wasn't foolish. Hearing Kisuke's words, he understood the implication. It required powerful Shinigami's power that would stay with Masaki until death. The only ones who could stay together inseparably for a lifetime were likely spouses. This essentially meant finding Masaki a powerful Shinigami as a husband. The thought was unbearable for Ryuken.
But Kisuke said expressionlessly, "Unfortunately... you have no other choice."
Hearing this, Ryuken's heart sank. He realized that without doing this, Masaki couldn't be saved. Though Ryuken loved Masaki deeply and wanted to be with her, her survival mattered more.
Kisuke continued, "The one with a choice..."
"...is you! Shiba Isshin!" Kisuke pointed at Isshin.
Then, Kisuke took out a Gigai, "This is made from human souls. It can transform the entering soul into a complete human. In other words, if you enter this, you'll become an existence between Shinigami and human. The opposite of a Quincy is a Shinigami, and the opposite of a Hollow is a human."
"Understand?"
"Using this Gigai, you yourself become the opposite existence of Ms. Kurosaki. Therefore, as long as you stay by her side, you can suppress the Hollowfication power within her, saving her life."
"That is your choice, Shiba Isshin."
"However, this is a choice with far more disadvantages than advantages for one party. While inside this Gigai, not only will you be unable to use Shinigami powers, you won't even be able to see Hollows. Moreover, once you enter..."
"...you will likely never be able to return to being a Shinigami!!"
"For this Gigai to suppress Hollowfication effectively, it must establish a Reishi 'connection' with both her own soul and the internal Hollow. This 'connection' is extremely strong. While tightly connected, you cannot leave the Gigai… until her soul and the internal Hollow are released from the connection."
"In other words… until Ms. Kurosaki passes away, you cannot leave the Gigai. Even if attacked by enemies, you cannot transform into a Shinigami to fight!"
Kisuke said with a grave expression, "Therefore, no one will force you to do this. The choice is entirely yours. You can refuse. But Kurosaki Masaki's life would then be uncertain. Of course, if you can find another powerful Shinigami to replace you, that's also possible. For example, the Shinigami beside you."
Saying this, Kisuke looked at Toshiro standing next to Isshin. Though Kisuke had been absent from the Soul Society for years, he kept close tabs on its affairs. Thus, he was aware of Toshiro's prominence.
Moreover, Kisuke personally sensed the might of Toshiro's Bankai during his battle with Aizen in the Living World. This close encounter further confirmed Toshiro's unfathomable strength, Kisuke wasn't confident of victory in a direct confrontation. Of course, in terms of strategy, Kisuke believed he wouldn't lose to anyone.
"So, Mr. Shiba, have you made your decision?" Kisuke asked.
Toshiro, Ryuken, and Kisuke all watched Isshin intently, awaiting his response.
Ryuken thought, 'This kind of deal offers only disadvantages and no benefits for a Shinigami. He probably won't accept. After all, accepting means losing Shinigami powers. How could he...?'
"Understood. I'll do it," Isshin said casually, crossing his arms.
"Huh?!" Ryuken and Kisuke were stunned.
For such a significant matter, they expected Isshin to either refuse or agree only after careful consideration. Yet, Isshin agreed without hesitation, as naturally as eating or drinking.
Though Ryuken sensed mutual fondness between Isshin and Masaki, he never imagined Isshin would go this far. Once Isshin did this, although he could stay with Masaki, potentially becoming a couple due to their close connection, it also meant Isshin would permanently lose his Shinigami powers.
Falling from a powerful Shinigami to an ordinary human with no power wasn't something anyone could easily accept. Yet, Isshin agreed without the slightest hesitation.
Unlike Kisuke and Ryuken's surprise, Toshiro wasn't taken aback. Even without knowing the original plot, Toshiro could guess Isshin's choice.
After years together, Toshiro understood Isshin's character deeply. Isshin was always someone who repaid a drop of kindness with a flood of gratitude.
Since Masaki saved him earlier, that alone made refusal unlikely. Moreover, Isshin already held fondness for Masaki. Doing this would bind them closely, potentially making them husband and wife.
For Isshin, making this decision might even bring a hint of excitement.
"That... wouldn't you reconsider?" Kisuke asked.
"I already said I'll do it!"
"Hurry up and proceed!"
"Your explanation was way too long anyway!"
Seeing Kisuke hesitate, Isshin couldn't help but chatter on.