^. Also id suggest hoarding coupons to finish ninja in one attempt (that doesnt mean you cant get free frags when available). Why? Because getting 20k ninja usually takes 4+ months of saving and getting free frags. During this time you never know what gets added and how(if) that shifts meta. This way once you are able to recruit naruto you know if he is still really good or not. If yes, you end up recruiting him at the same time you would by getting him frag by frag when spending cp. If not and you kept on spending cp on frags each event cycle you might end up wasting resources. Also getting him in one go allows you to potentially make use of fukurokumaru rebate.