Hey,

You need 1 Secret Scroll Page to unlock those, or 100 Secret Scroll Plate Fragments to make 1 Secret Scroll Page.
I would recommend to unlock Ferocity 1st. As that gives Initiative and Critical.

Currently Time Limited Ninja Recruitment offers Secret Scroll Optional Pack II.
There you can choose if you want 10x Secret Scroll Page fragments, 14x Secret Scroll Page or 10x Mantra Elixir.