[Theory] Surpassing Bankai, It's Predicted already.

[ziggyZ]

Yamamoto was stubborn, and we didn't see everything he could do, and why would he use such a power? It was during a era of peace, and most likely, not every knew about it besides a select few? Also most of the captains are pretty knew, besides a couple. A move like FGT would be a last resort.

I mean against Llyod. He went all-out, he rose the dead to beat him. So even though we didn't see everything he could do (Kido, Hakudo, etc), what you're talking about is a Zanpakuto tech, and he showed everything of his Zanpakuto, so if it existed, he would've definitely used it. Especially when realized that was the fake Yhwach - he knew he was at death's door, so why not use it? 'Cause as you said: it's a last resort, and that would've the perfect time to do so.

 

[Pure Logic]

Could take time to prepare, and Yamamoto had to much pride, and if he did use a move like FGT, then he would be nothing but a old man, and anyone could take him out, Also his Bankai is OP, Bach just got the upper hand on him, and Yamamoto didn't know what to do. He's fought Bach before, and he thought he wasn't going to have a problem. Also how come he didn't heal his arm back? Pride.... His pride blinded him, and he was defeated.

 

[gazz uzumaki]

I mean against Llyod. He went all-out, he rose the dead to beat him. So even though we didn't see everything he could do (Kido, Hakudo, etc), what you're talking about is a Zanpakuto tech, and he showed everything of his Zanpakuto, so if it existed, he would've definitely used it. Especially when realized that was the fake Yhwach - he knew he was at death's door, so why not use it? 'Cause as you said: it's a last resort, and that would've the perfect time to do so.

Not necessarily. If his bankai alone is enough to destroy the soul society if used too long, then learning a zanpakuto tech like that would have wiped it from existence in an instant. Also, he may not have known about the technique. Their zanpakutos won't tell them anything about the tech, and Ichigo only learned about it from his father.

 

[ziggyZ]

Not necessarily. If his bankai alone is enough to destroy the soul society if used too long, then learning a zanpakuto tech like that would have wiped it from existence in an instant. Also, he may not have known about the technique. Their zanpakutos won't tell them anything about the tech, and Ichigo only learned about it from his father.

Destroying Seireitei is most likely a hyperbole. After-all, he was swinging Zanka no Tachi: North (something which is said incinerate all) quite a few times, yet it didn't do much damage to Seireitei as a whole. Plus, Ichigo's final power-up is hyped to be way, way stronger than Zanka no Tachi, and if Zanka no Tachi is said to strong enough to destroy Seireitei, then when Ichigo fights Yhwach/Uryu, it makes no sense how SS will stay intact. Hence it's a hyperbole.

And it makes no sense if Yamamoto doesn't know about it. He was one of the original Shinigami, one of the original member of the G13, and arguably strongest person to exist. So someone who's lived over 2 millenia and not know of such a thing is incomprehensible. Furthermore, why would Isshin know of it and not him?

 

[gazz uzumaki]

Destroying Seireitei is most likely a hyperbole. After-all, he was swinging Zanka no Tachi: North (something which is said incinerate all) quite a few times, yet it didn't do much damage to Seireitei as a whole. Plus, Ichigo's final power-up is hyped to be way, way stronger than Zanka no Tachi, and if Zanka no Tachi is said to strong enough to destroy Seireitei, then when Ichigo fights Yhwach/Uryu, it makes no sense how SS will stay intact. Hence it's a hyperbole.

And it makes no sense if Yamamoto doesn't know about it. He was one of the original Shinigami, one of the original member of the G13, and arguably strongest person to exist. So someone who's lived over 2 millenia and not know of such a thing is incomprehensible. Furthermore, why would Isshin know of it and not him?

Yamamoto living over 2 millennia doesn't mean that he's knowledgeable of everything there is to know about a zanpakuto, that solely belongs to Oetsu Nimaiya. And Isshin knowing a technique like that while Yamamoto does not, may mean it's a secret passed down to those in the Shiba clan. After all, someone must have told Isshin as well, because his own zanpakuto was reluctant to tech him as well.

 

[ziggyZ]

Yamamoto living over 2 millennia doesn't mean that he's knowledgeable of everything there is to know about a zanpakuto,

He would've known about it by now because the fact that he's been alive for so long means he would've seen everything by now. Especially if it's something like a tech similar to FGT, 'cause the Reiatsu exerted from a tech like that would be felt by Yama miles away.

that solely belongs to Oetsu Nimaiya.

Someone like him would definitely enlighten the likes of Yama (one of the strongest) about something like that.

And Isshin knowing a technique like that while Yamamoto does not, may mean it's a secret passed down to those in the Shiba clan.

Or it may just be a tech restricted to him and his Zanpakuto. So his Zanpakuto told him.

After all, someone must have told Isshin as well, because his own zanpakuto was reluctant to tech him as well.

Engetsu didn't teach it to him because he most likely didn't want to lose Isshin. So it's pure speculation if someone else has a tech similar. Plus, Isshin may only know of it since Engetsu might've mistakenly told him that there's a tech far greater than what he already knows. Or, his Engetsu might've told Isshin about this power and asked him if he wants it, and Engetsu was certain he'll decline the offer due to it's drawback but Isshin actually wanted it, and shocked by his eager Engetsu decided not to give it to him.

 

[gazz uzumaki]

He would've known about it by now because the fact that he's been alive for so long means he would've seen everything by now. Especially if it's something like a tech similar to FGT, 'cause the Reiatsu exerted from a tech like that would be felt by Yama miles away.

Someone like him would definitely enlighten the likes of Yama (one of the strongest) about something like that.

Or it may just be a tech restricted to him and his Zanpakuto. So his Zanpakuto told him.
Engetsu didn't teach it to him because he most likely didn't want to lose Isshin. So it's pure speculation if someone else has a tech similar. Plus, Isshin may only know of it since Engetsu might've mistakenly told him that there's a tech far greater than what he already knows. Or, his Engetsu might've told Isshin about this power and asked him if he wants it, and Engetsu was certain he'll decline the offer due to it's drawback but Isshin actually wanted it, and shocked by his eager Engetsu decided not to give it to him.

I think we both should call it quits. We're getting nowhere and we are both only going off speculations here and not actual proof. We can only agree to disagree.

 

[Pure Logic]

We shall see later in the manga, a lot of things have to be explained, I feel like Kubo needs to start closing these questions and not leave us hanging.