Warning! Spoilers for Infinite Frontier #0 and Suicide Squad #1 ahead!
Infinite Frontier just gave the world of Batman comics its biggest change in years by destroying Arkham Asylum, killing several longtime DC villains in the process. These are all the bad guys who perished during the attack on Arkham, as well as a few who managed to make it out alive.
Arkham Asylum has been a staple of the Batman franchise for decades as the Dark Knight’s go-to place of imprisonment for his often deranged enemies. Consequently, it’s also been the site of some of Batman’s most iconic stories, both in comics and other media, which is why the asylum’s apparent destruction in Infinite Frontier #0 is so shocking. However, it wasn’t the flames that killed most of the inhabitants; before exploding, the asylum was first flooded with a silent version of the Joker toxin that took out dozens of guards and inmates, including Bane, a major Batman villain and one of the Dark Knight's greatest foes.
As it turns out, the inmates of Arkham weren’t the only villains present during the attack. Suicide Squad #1 by Robbie Thompson reveals that Task Force X was also on-site, though they weren’t the ones behind the Joker toxin. A team consisting of Peacemaker, Bolt, Film Freak, and Shrike is sent in to retrieve Talon, a former member of Batman's Court of Owls who has since forgotten who he is. However, though Talon may have lost his identity, he’s lost none of his skill, as he expertly slices Bolt’s throat with a toothbrush and leaves the teleporter for dead. Film Freak and Shrike fall victim to the Joker gas not long after, and while Peacemaker and Talon are still standing by the issue’s end, it’s unclear as of yet if they make it out alive.
Aside from those mentioned above, the only other villain explicitly shown to be in Arkham during the attack is Professor Pyg, who is briefly seen locked in his cell in Infinite Frontier #0. It seems very unlikely that Pyg could have escaped in that short amount of time. However, the villain appears with a repulsive new form in Future State, which is heavily implied to be in the same timeline as Infinite Frontier #0 since the issue ends with Simon Saint and Scarecrow discussing the implementation of the Magistrate program. Given this, it would seem that Professor Pyg did manage to make it out of the asylum in time. It’s also possible that the version of Pyg seen in Future State is just someone else using his mantle, but as of now, there’s no way to be certain.
In addition to the villains who perished, countless employees and guards also died during the attack. Given the subtle connections to Future State, it seems that the Arkham Asylum invasion may be the event that triggers the massive changes that come to Batman's city in DC’s future.