Batman would probably isolate himself at first. He'd retreat to the Batcave to analyze the situation. He might feel a sense of guilt, thinking he should have seen the betrayal coming. After that, he'd start planning his counter - move. He'd use his vast resources and knowledge to expose the truth behind the betrayal and take down whoever is behind it.
Bane. He was born and raised in a prison called Peña Duro. He was forced to endure harsh conditions from a young age. To survive, he developed great physical strength and a cunning mind. He has a vendetta against Batman. His origin story fuels his desire to break Batman both physically and mentally. He is often seen as one of the most physically imposing of Batman's foes, and his backstory gives him a unique motivation for his actions.
Catwoman's origin has different interpretations. In some versions, she grew up in poverty and turned to thievery as a means of survival. Her skills as a cat burglar are what initially put her at odds with Batman. Over time, she has also developed a complex relationship with Batman, sometimes being an ally and other times a foe. Her feline - inspired persona and acrobatic skills make her a unique and iconic Batman villain.
The Joker is a very well - known main villain. He's completely unpredictable and his chaotic nature provides a great contrast to Batman's order - seeking personality.
He might isolate himself from the League at first. Batman is used to working alone, so he could retreat to his Batcave and plan his next move. He could also start to prepare counter - measures in case the situation escalates and the Justice League becomes a threat to him.
Batman would be heartbroken. He has trained Robin and sees him as a partner and almost like a son. He would first try to talk to Robin, to find out what made him turn evil. He would hope that he could reason with Robin and bring him back to the good side.
Batman would probably first try to contain the situation. He'd use his resources as Bruce Wayne to spread misinformation or counter the revelation. He might also go on the offensive against Scarecrow to stop him from spreading the news further.
At first, Batman would be shocked and a bit confused. But quickly, his detective instincts would kick in. He would view the deaged Joker as a new and unexpected threat. He'd start gathering information about how the deaging occurred, in case it was part of a larger, more sinister plan. Batman would also be very careful not to underestimate the deaged Joker. He might try to isolate the Joker in a secure location to prevent him from causing chaos in Gotham. And he'd be constantly on the lookout for any signs of the Joker's old, devious self emerging from this new, younger form.