like you said 60 seal scrolls to get a rare
you should draw all you seal scrolls in kage treasure for now because the best ninjas is in kage treasure.

you will get seal scrolls faster if you increase you power and participate in gnw every week.

note: being f2p required from you to be smart
for example, you should know the right time an events to use scrolls coupons and refining rune :victory: :D