Though Batman is often portrayed as this mysterious lone wolf figure, that's simply not the case for the vast majority of his comic book appearances. At all times, Batman is surrounded by allies, with some of his closest ones often being colloquially referred to as the "Bat Family." Whether it's Nightwing, Batgirl, the many different versions of Robin, or even Alfred, Batman also has friends around him. And with Batman making an appearance in Suicide Squad: Kill the Justice League, it would only make sense for his Bat Family to follow him there too.