WARNING: The following article contains spoilers for Detective Comics #1002 by Peter J. Tomasi, Brad Walker, Andrew Hennessy, Nathan Fairbarn and Rob Leigh, in stores now.
The arrival of the Arkham Knight in the DC Universe has thrown Bruce Wayne's life into disarray. The armored warrior intends to break the symbol of the Bat for good, believing it's a poison coursing through Gotham's veins.
Using an order known as the Knights of the Sun, as well as a day bomb meant to eliminate the Bat's biggest weapon, the night, it's clear he knows Batman inside out. While DC has done well to keep his identity a mystery, clues suggest it could be the future Tim Drake, Savior.
This Tim has quite a storied past. In "Titans of Tomorrow" he became a vengeful Dark Knight after Bruce's death and the eventual end of the Bat-family, which resulted in him being thrust into the present after escaping Mr. Oz's (Jor-El) prison along with the current version of Tim. Future Tim would end up trying to kill Batwoman and going to war with the Bat-family, as he needed to stop a mysterious impending disaster.
However, he was sent back via Hypertime only to return on a new mission to kill Jon Kent. Here, he turned into Savior, as he felt it was his duty to preserve the future. Future Tim, however, absorbed Jon's solar flare, the very thing that would kill millions years down the line, and with this crisis seemingly averted, Hypertime once more claimed the fallen warrior, at peace at last. But subtle clues hint he's back and hunting Bruce now.
Arkham Knight is essentially the opposite to the Dark Knight. Instead of using his troops for good, the Knight uses his soldiers as part of a twisted crusade -- something future Tim did with his legion of Batmen in Gotham. But it's the "attack during the day" mentality that is an even bigger clue, as he said in the past he wanted to "operate in the light of day and emerge from the rising sun not as a bat out of hell... but as a savior." This was written by Peter J. Tomasi for Teen Titans #15 "Super Sons of Tomorrow" arc alongside Patrick Gleason, and, with Tomasi on story here again, that moniker gets another reference.
Here, Damian Wayne investigates the Knight's lair in Aparo Bay, only to be abducted and taken to a mysterious dungeon. The Knight has a shrine to the symbol of Robin -- from paintings on the wall to an actual medieval Robin suit -- and goes on to shockingly call himself Gotham's "savior." Coupling this with the Knights of the Sun, it seems Tomasi is building on the foundation previously laid.
It might be that Tim has become disillusioned with what Robin stood for and how Bruce doomed him to a life of war the moment he gave him the mantle. As the Knight keeps addressing Damian as his junior, it seemingly repeats the teachings he tried to impart on Damian in the future before Jon accidentally killed the latter.
As for Tim's potential reasoning, Flashpoint did alter reality, so we can see him simply wanting to make Bruce pay for all these calamities that befell him. After all, future Tim's missions have become a burden and he's made it clear in the past he wishes he could change how he became a soldier.
On the last page, while we don't see the Knight's face as he takes his mask off and tries to recruit Damian, the hairstyle hints it might indeed be an older Tim. He's always seen Damian as a protege, and tried to influence him decades later when the boy would grow up to become the World's Finest with Jon, and history might be repeating itself. Ultimately, we don't know where or when Hypertime took Tim, but we can easily see him becoming deranged enough to now be on this extremist path filled with regret.