Not sure if you can really make it out in the picture, I only know because I spent a good while trying to read the title of that book myself and repeatedly knocking it off the stack of books its on instead.
It was a reference to SBFP but no, no a beasthood build would not be a good advance against Kos, High Strength with the Beast Cutter would be preferable, because the Beast Cutter moveset transformed is really close to Kos's moveset with his yo-yo scythe so it's good to match him with it, I'd assume.