I don't even know what's he's done so far, care to fill me in captain?
Until powerful translations roll out, I can’t give any nitty gritty details because I, too, lack them, but just from my very meager knowledge of Japanese and contextual cues:
At the start of the event, who we thought was Nobunaga was actually Nobuyuki disguised as her and using her name.
Under the identity of his older sister, he gets in an argument with Hijitaka Toshizo, Vice-Commander of the Shinsengumi.
The Real Nobbu appears and gets Very Angry at Nobuyuki for using her name and identity, especially to cause TROUBLE.
However, Nobunaga was not going to take this shit from Hijitaka, even by proxy, so she took issue with it, because she’s STUPID.
Okita Souji, Commander of the Shinsengumi, also STUPID, wasn’t going to take this defensiveness from Nobunaga (by double proxy) and so she also took issue.
Nobbu and Okita REALLY escalate it.
They turn to you, the protag
No matter your choice, you bathe this fire with oil and it escalates further
but just when you thought it was over, Nobuyuki did Something and Stole Something
Nobunaga was like “hey what the fuck man”
Nobuyuki was like “sorry onee-san but fuck you”
He reveals his two ACCOMPLICES
It’s fucking Thomas Edison and Nikola Tesla.
Nobuyuki had them IMPROVE on the design of the mass production Chibi-Nobbus to create the powerful Meka-Nobbu and NobbUFO, in addition to the new Nobbusengumi and Guntank Nobbu models.
Oda Nobuyuki, Edison, and Tesla create a powerful trio, and they have an army of Nobbus.
This triggers a second war, them versus Nobunaga, Okita, and Hijitaka.
Who also have some Nobbus of their own
Tomorrow, there’s a THIRD war scheduled.
Nobuyuki did all this. He directly caused two wars, one after the other.
By dressing up as his sister.