Hi! At the moment, the two ninjas are relatively new. However, like any other ninjas, even super rares, they will be available in events in the future. I don't know the exact date at the moment, but it will definitely appear later on in the future. Both ninjas are quite good though! I myself wanted Madara, but got Kurama instead. At first, I thought it was sad until I found a really good team XD

~Jib

Jib Edit: Let me know if you have any questions! I am also available through private message =p