Fate/Stay Night: Unlimited Blade Works

[Ryllharu]

She's probably the strongest human swordfighter in the franchise. The authors claim she is as skilled as Shiki from Kara no Kyoukai. Actually the other way around. Shiki is as strong as, "the legendary swordswoman from Fuyuki." Taiga is a fifth dan.

Saber is just that much better, but that's still saying something.

edit:
One can deduce that since Taiga is 24 years old, she has been promoted in Kendo rank at the earliest opportunity for each rank, ever since she was 13.