[FGO] - Uesugi Kenshin BGM 

I got that idea too, actually.

Ong

It was revealed that it was Kagetora mom over Uesugi Kenshin, avatar of Bishamonten. But the reality is that the mother is simply possessing the body. If you noticed this event, there's a lot of hijacking over someone's body. Imagawa Yoshimoto, the main enemy, is not even the said person, but his son, Ujizane Imagawa. He borrowed his father's body with a goal to clear his father's name. Which the tale of his incompetence being defeated by Nobunaga small forces. This defeat culminated of everyone's thoughts of Yoshimoto Imagawa being a clown, even though it was written in history that he was a strong and discipline warlord. But the general populace sadly accept the false foolish what a joke version. The body of Uesugi Kenshin is own by Nagao Kagetora. Her mom slip to take upon the mantle, being a fanatic devotee to the war god. When you summoned Kenshin, it still the Kagetora we know and loved.

Remember one thing, Shigen doesn't like girls...

Shichisei-shini by spiral ladder

No. Same person, different name. Nagao Kagetora was the name of Uesugi Kenshin before Kenshin was adopted by Uesugi Norimasa