Suicide Squad: 10 Biggest Questions Left Unanswered
6. What Is The Joker & Batman's Backstory?
The Question: The Joker and Batman don't have any direct interactions in the movie, either in the past or present, though the film is quite obviously setting up a Joker-Batman battle in the Dark Knight's solo movie. So, what exactly is their history here?
The Likely Answer: Though the movie didn't reveal it as many expected, many suspect that Jared Leto's Joker may in fact be Robin aka Jason Todd, with a traumatic prior event turning him insane. How this would connect to Robin being dead in the DCEU, however (evidenced by his vandalised suit in Batman v Superman and Harley Quinn's introductory text stating that she killed him), is anyone's guess.
It's been suggested by some that Todd's Joker could even be the second iteration of the character after Batman killed the first, but that's decidedly more of a stretch.
Whatever The Joker's true identity is, it's clear he and Batman have beef over Robin's demise, and that's probably the primer for their inevitable cinematic throw-down later on.