Hello!

As far as I remember, those ninjas who were placed as the reward for 3v3 Arena are placed and released again in different events where players can get it for free, at least for some of them. If you want to request for them to be placed on other events, you may go to our News Section and look for the New Events Feedback threads to give your thoughts about it. I will try to bring this up to my superiors too for you all. Thank you.