Original Himetsuru Sword from the end is junk. I haven't gotten a Takenomata Kaneko Sword from the end, but that looks like it might be useful for Uesugi Kenshin and useless otherwise. A comment on the Japanese Wiki makes it sound like the damage bonus might also apply to UR Dragon of Echigo. I'll check if I can get one.

Kaneko Sword (P) from the port, on the other hand, looks to me like top tier endgame quality gear. The Google translate of the Japanese wiki didn't make the description clear, but once you check the item's page, people say explicitly that it means a single target attack turns into two targets, two turns into three, and three turns into four.

Throw in that you increase Uesugi Kenshin's attack by 150% and that also turns Uesugi Kenshin into a top tier general worth comparing to Tiger of Kai, Sanada Yukitaka, and Master Strategist. I'll have to test it when I get one to see if that's really what it's doing. As of yesterday, Uesugi Kenshin was really only useful for reflect damage.

The opponents are also notably easy, so I pull all but Master Strategist off the team so that the battles can end faster rather than having to wait for a bunch of skills to stack.