well as far as i can tell being a S252 player means that it cant be called mid-game anymore xD well anyways with those ninjas as i can see you have 2 good teams you can built up .... Mei Terumi , Mabui , Ten Ten Gnw with water main ....

or either a Ay team with jinpachi , samui and lightning main / or other versions with darui , or even using earth main instead.But like nah bro go save 12k coupons or so and get yourself a good ninja. All you can built right now are f2p teams which wont really be useful unless you got tons of power and initiative to beat your opponent with brute strength