Go for power I am a f2p and I have almost 70 k power and 101 ninjas , ninjas will come anyway , while a lot of ninjas will become outdated you still will have power . Power is better than ninjas . It's useless to get every ninjas that come out if everyone beats you . Make sure you have some power behind you if you go for ninjas . But overall power is better . My advice is to stack your coupons and at the every begining of the mounth go for lucky bord , you get a lot of power and if you want get some ninja .