actually that having 4 characters wouldn't really give you copyright.... Who ever told you that is wrong... NOW! if you made 4 characters with Blue purple red orange, made them eat pizza, and saying "COWABUNGA" then you might get Copyright. put for having 4 characters with ninja turtles weapons... not really..... Plus from the looks of it the russian character only has one sword and the USA character only has one nun-chuck Sooo your good :) plus if you don't want the black dude have Sai's their are other ninja weapons ( Kamas, Flighting Fan, and the Shoge Hook with 13" Chain)