Connection Of The Six Realms Of Buddhism to Bleach!!
For Buddhists, these six realms represent all possible states of existence. They were traditionally conceived as real places, but can also be interpreted symbolically. The animal, ghost and hell realms are all places of punishment for previous sins, whereas birth in the heavenly, asura, or human realms comes through the accumulation (and spending) of karmic merit. Life in any of these realms is ultimately impermanent—one does not suffer forever in hell, nor enjoy eternal bliss in heaven.
So with this latest chapter, it was pretty much confirmed that the races of Bleach fit the realms of reincarnation in Buddhism. They would fit like this:
But, I'm continuously finding myself having trouble figuring out where Zanpakutou fit anywhere. To me, they must be their own race since they have their own mind, body, and spirit which are separate from the Shinigami's. Kubo does often just refer to Zanpakutou spirits as "Shinigami powers," but there must be more to it. As we learned from the Quincies stealing the Shinigami's Bankai, even without their inner Zanpakutou they can still use the rest of their powers.
This is where the crack comes in. I think that Zanpakutou are actually sinners from Hell. I believe that Hell is actually similar to the Dangai, being an intermediate area where souls are kept to be fused with incoming good souls to become their inner Zanpakutou spirits, serving them until death as their weapon. As such, the diagram would be this:
This would explain why only some souls have the ability to manifest Zanpakutou (because there was a sinner waiting to be fused to them). Of course, the sinners would also forget their past like the Shinigami, which is why they don't still act like insane criminals.
The main reason I thought of this was because of the amount of Zanpakutou which reference hell and other mythological beings associated with suffering, etc. Of the 14 Bankai we've seen, 2 of them directly reference Hell (in name alone, there are more in terms of ability names and appearance), and 4 more reference wrathful beings. Zanpakutou also fit very nicely in the diagram of the six realms, explaining why Zanpakutou and Hollows seem to be so easily compatible, whereas once a Shinigami gets Hollowfied (as in, once a hole opens in their chest) they explode from Soul Suicide.
Also, most Zanpakutou have an animal to represent them. That doesn't really fit with Shinigami, since they're first and foremost entirely human. However, both beasts and Hollows are animalistic, so it would follow that Hell beings should also be animalistic. Of course, not all Hollows are animals, so it would be the same for Zanpakutou. They're just animalistic in appearance but (unlike Hollows) not in nature.
Ultimately, this would mean that there are 5 types of being. Humans and animals are the same, living in the same realm and such. I mean, humans are animals after all. Y'know how Kubo is with the number 5 these days.