the OC's I put in here are what I call "entry OC's"
they usually the first OC of a series, and, in a way, more or less, are the same template of a character mismatched to fit the universe, and often are connected to the main story line and main characters. They often follow 1 theme: having panther-like qualities and powers that find source in either darkness, shadows or death.
These OC's are used to learn the style, time-line, and other qualities of the universe before going into "geniune OC's" which usually have nothing to do with the main story or main characters of the universe, the best they can do is interact with each other or very minor characters of the universe. I consider my "geniune OC's" my true OC's, rather than the "entry OC's" which are made in pure fun.