Isshin - Uncle Shiba ?
The uncle being Isshin has big plot holes that needs to be filled in before this turns out to be true.
Kubo said that all the bloodlines would become clear. We are now starting to see the beginning of that. So who could be this "uncle" Shiba? We all know who would make the most sense but you never know what Kubo could pull with people being related.
Isshin facts about:
1. Isshin has a captain like haori but its completely different from gotei 13 captain or Royal Guard
2. Isshin has been hiding information regarding the Kurosaki family from Ichigo
3. Isshin's zan name is "Engetsu"
4. Isshin's zan ability (or what has been shown) is Getsuga Tensho
5. No Gotei 13 captain (other than Aizen and Urahara) has yet to make a connection between Ichigo and Isshin via -
a. Kurosaki name
b. Zan name (Zangetsu/Tensa Zangetsu/Engetsu)
c. Zan ability (Getsuga Tensho)
However these points can be countered if -
Now the fact number 5 is the main problem with the theory Kukaku is referring to Isshin as uncle (although there are loop holes). As of now no one in SS has made the connection between Ichigo and Isshin. This hold true for Yamaji (the oldest shinigami to date by appearance). He has seen Ichigo do a Getsuga Tensho in FKT, and if Isshin served as a captain under Yamaji in the last 1000 years (or in the original divisions 1000+), then Yamaji of all people should have made the connection.
Then there are other who should have made the connection -
- Sasakibe, who was alive and well in FKT (guarding the barrier) and thus should have seen Isshin during the fight
- Unohana, who was alive and well in FKT (healing) and thus should have seen sensed Isshin's reiatsu
- Every injured captain (ranging from "young" Hitsugaya to "mid" Shinji to "Older" Shunsui) would have been conscious (as Aizen puts it), hence should have seen Isshin or felt his reiatsu
What this proves is neither Yamaji, Sasakibe, Unohana, Shunsui etc know Isshin at all although the loop hole is they have seen Isshin, but he had a different surname, didn't real his zan power or even his zan name and hid his reiatsu from them. This sounds farfetched but possible.
Isshin was from the Royal Palace either as a Royal, or as a EX-Royal Guard (who probably left 1000+ years ago even before gotei 13 was formed). As a RG, if it was within the last 1000 years, he would have had to come down to SS once or twice (seeing as by Shunsui's word they did) thus other captains should have seen Isshin. Although the loop hole again would be - they have seen Isshin, but he had a different surname, didn't real his zan power or even his zan name and hid his reiatsu from them.
So is -
EX-Royal Guard theory possible
Yes, but makes no sense why did he leave or even how without anyone capturing Isshin. Although this would mean Isshin meet Ichigo's mother "Masaki" (Bach's daughter) in real word 16 years ago at the very least. However it makes no sense to me what was Bach's daughter doing in the real world, or why wasn't she in the same time limit dilemma as Bach and VR is.
Royal theory possible
If Isshin is a Royal how would Isshin be related to a Shiba!? The only loop hole in this would be if Kaien parent was actually Isshin's sibiling (older or younger) who set up the Shiba clan after leaving the Royal Palace 1000+ years ago. Therefore Shiba's are in fact Kurosaki's and not the other way around. Only problem with this is why does Kaien have a different zan compared to Ichigo and Isshin?
As of now all the theories I've put is Isshin is blood related to the Shiba. However its also possible he married into the Shiba family except it makes no sense. Ichigo is partly human (or we are lead to believe he is) hence one of Ichigo's parent have to be human (Normal or Quincy or Fullbring).
Thus theories would involve -
Bach (a Quincy) married SK's daughter thus Isshin was born. Isshin married a Shiba (Maskai) and this Ichigo was born. Ichigo gained his Quincy power through Bach (grandfather) and shinigami power through SK's daughter (grandmother).
Kaien's parent (head of Shiba clan), Isshin and Maskai are sibling. Masaki one way or another (say captured by VR) meet Bach and had Ichigo. However Maskai left with Ichigo to the real world due to Bach's ill nature and Isshin (her brother) adopted him.
Kaien's parent (head of Shiba clan), Isshin and Bach are sibling. Bach ditched the family 1000+ years ago and say one way or another joined the Quincy - for example by saving a Quincy from hollow attack. He then gained Quincy power and when the shinigami turned on the Quincy fraught back since in his view the SS is being unjust. And 15 years ago, he had a son with a Quincy women thus Ichigo was born with pure Quincy blood (and family shinigami genetics passed on). However the Quincy women realized her son would be in danger of being killed by SS, and certainly will if he follows in Bach's footstep. Thus she escaped with Ichigo and came to the real world. Isshin found her and took Ichigo in due to being his nephew.
Whats true, and Kukaku's words point out, is uncle isn't fond of the Royal palace (and most likely the SK) for a reason unknown to us and/or would be sad because Ichigo will find something about said uncle that relate to the Royal Palace. Thus we can conclude said Uncle is a Ex-RG or has royal ties.
However I seriously doubt Ichigo is going to lose sleep if he turns out to be related to the Shiba clan (or even Soul King) via Isshin. There is something Isshin is still hiding regarding Ichigo's birth (Maskai being a Quincy wouldn't be shocking enough unless she was killed by Shinigami side). I will stick to the notion either Isshin and/or Maskai isn't Ichigo's biological parents until proven otherwise. Thats the only thing that would shake Ichigo down to his core and polarize him again SS.
At this moment in time Ichigo's loyalty is the main factor in this war and Tite has to display some sort of crisis within Ichigo.
Credo to Bliz >> :shrug: