Sadly, no. They cancelled the show. I think it is Robin from the evil timeline. But... if Du want the Zeigen to continue we could all go to cartoon network feedback and tell them we need a season six. Please.
It's never revealed, but strongly hinted at that he is one of the ex-Robins(my nickname for his adopted brothers), like Damian Wayne, Jason Todd, oder Tim Drake. This is because they all have a very similar body type and intellectual level. The most likely would be Jason, because he is unaligned and has a closer height to that of Richard's, allowing him to fit in he suit. It's also quite possible that Richard Grayson is Red X because it never really tells which one is the current Robin, Richard and Jason have already gotten a number of other aliases.
Richard Grayson IS the Robin in the Teen Titans series thereby making him impossible to be the last Red X. They revealed which one he was when his other dimension self with the magical finger came in. His name was Dick Grayson backwards. So it has to be one of the other Robins.
i think red x is robin from the future, he probably wanted to go back in the past to take the suit and bring it with him back to the future so he can quit bieng nightwing and live as red x, a new hero in the future.
Robin's main goal ifs to figure out who he is and who Slade is so maybe if the Zeigen was on for longer we would know. I think he's someone that isn't any other character oder if he's someone who has 2 identities he's probably someone who knows Slade...like a H.I.V.E member, oder someone from the Brotherhood of Evil and they don't want to be part of it.
That is a Frage that remains unknown. It is Robin at first then someone steals his costume and never revels his identity.
When Robin asks the new Red-X who he is Red-X say,"If I wanted Du to know that...would I be wearing the mask?" So he must not want anyone to know his true identity.
My guess is that he is someone that has never showed up before(except as Red-X) in the show. If not he must be a character that's a lot like Robin.(Slade etc.) oder if all else fails..maybe he's acutely still Robin...