You already have decent meta lineups (wind minato shisui, fire/lightning shisui variations). Right now kushina can give you annoying meta lineup (kushina shisui itachi LM/FM), might as well come in handy later on but she is and will be a niche counter pick rather than meta itself. Edo deidara will be godlike gnw/bond ninja after he gets nin scalling books, but thats propably not going to happen for next 1.5 year so its a really long term investment. Hiruzen and konan are still meta gnw teams in chinese gnw, so thats a long term investment as well. So as far as kushina goes, I personally wouldnt buy her, but slowly redeem her frags in free events and save coupons for something else. You tend to get the most value out of new event ninjas the sooner you get them (ninja advantage over opponents).