WARNING: This article contains SPOILERS for Detective Comics #979
Tim Drake has assumed the mantle of Batman, but he's a Batman unlike any other - an OMAC Batman. Not the brainchild of Bruce Wayne, but Ulysses Hadrian Armstrong, and who along with Brother Eye has a sinister plan to save Gotham City.
The Rebirth era of Detective Comics has been a real rough run for Tim Drake AKA Red Robin. Tim Drake apparently died in the first arc, only for it to be later revealed he was actually kidnapped by Mr. Oz. Tim eventually managed to escape that prison with the help of his future-self - a Tim who had become the future Batman but in doing so witnessed the downfall and death of the Bat-Family and was subsequently driven mad. And after preventing this Future-Tim Drake from killing Batwoman, the Tim of the present made it his life's purpose to prevent that terrible future from happening.
But Tim's determination to prevent one bad future might be creating another that's even worse - much worse.
In the last couple issues of Detective Comics, Ulysses - the Colony's tech guru and total jerk-face - has been trying to tempt Tim with the knowledge and technology he downloaded from the Future-Tim's Batsuit (like the Brother Eye, for instance), promising that by working together they could make Gotham City safe forever. So far, Tim has withstood temptation and hasn't taken Ulysses up on his offer.
But Ulysses isn't really the sort to wait around for a 'yes' and instead forces Tim to comply - transforming him into an OMAC with a nano-virus created by combining Brother Eye's programs and Ulysses' own nano-tech.
Created by Jack Kirby, the original OMAC was a singular figure named Buddy Blake - a mild-mannered office worker who was transformed by the satellite, Brother Eye into a super-powered "One Man Army Corps" or OMAC. More recently, however, the OMAC concept was reincorporated into the DC Universe as an infection spread by a nano-virus that when contracted transforms its host into a cyborg. These OMAC cyborgs are all connected via a hive-mind that's typically controlled by Brother Eye - a super-advanced computer surveillance program that in most modern DC Comics canon was created by Batman as a fail safe to keep the Justice League in check, but in the Rebirth continuity appears to be a creation of the future-Tim Drake that he used to turn Gotham City into a police state.
In Detective Comics #979, Tim fights back against the OMAC programming - which has also infected and transformed the Colony's soldiers - trying to wrestle control of his mind back from Ulysses and Brother Eye. To combat Tim's free will and make him more willing to see things his way, Ulysses floods Tim's brain with all the trauma endured by the Future-Tim. This transforms Tim into not just an OMAC, but an OMAC version of that twisted Future-Tim Drake - fully committed to saving lives by any means necessary, even if that means assimilating all of Gotham City into the OMAC Project.
Running a new program - "PAX BATMANA" - Tim assumes the appearance of an OMAC-infused Batsuit, complete with a large, glowing red eye. As a horrified Cassandra Cain looks on, Tim insists this is the "real me... maybe even a more refined version ... it's me, it's Tim." He tells Cass to give Batman a message, saying he's "doing this for all of you" but warning them "don't get in my way."And with total control of the OMAC fleet as well as Brother Eye, whoever does get in his way is sure to suffer a similar fate - assimilation or death.
Tim Drake as he was no longer exists - now he is an OMAC, infused with Brother Eye; he is Gotham's savior, it's new Batman.