Quote Originally Posted by LastCetra
Well if you look at some of the recent trailers you'll see bits of dialogue that show he's back.
"I won't just be a memory" being the most well known one at this moment in time
Teen Titans Ep. "Haunted"
Robin is haunted by the "ghost" of Slade, his deceased nemesis. This "ghost" has the ability to hurt Robin while seeming impervious to his attacks.