How Every Robin Can Appear In The Batman 2
8. Mystery Approach
The challenge in introducing Robin is the threat that his presence might alter the tone of the film or that he could steal the show entirely. While nobody wants a repeat of the Schumacher films, Nolan's approach of toying with the idea but overly downplaying it is equally bad.
However, The Batman offers up the solution in it's own storytelling. If Robin (not unlike Riddler) is introduced as a mystery character operating independently of Batman, the audience once again gets to follow Bruce's POV as he pieces together the identity of his new ally while also dealing with the threat of the film's primary villain... whoever that turns out to be (*cough* Court of Owls *cough*)
A movie like this might be best served by drawing influence from 2003's animated "Mystery of The Batwoman"; a picture in which Batman has to uncover the identity of a reckless and unwanted new ally. Characters like Dick, Jason and Tim could be introduced throughout The Batman 2 and each be teased as possibly Robin before, like in the animated feature, they are revealed to be working as a group.
This mystery approach offers the chance to introduce most of the main Robins while preserving the detective elements and potentially sparing the audience the tedium of going through the motions of Robin's origin.