The New 52

After the events of the 2011 "Flashpoint" storyline, as part of The New 52, reality is altered so that Firestorm's personal history is completely restarted. Ronnie is now introduced as a high school senior and the captain of the football team. During a terrorist attack on their school, Ronnie's classmate Jason Rusch produces a vial given to him by Professor Stein, which contains the "God Particle," one of Stein's creations. The God Particle transform both Jason and Ronnie into Firestorm, and the two teens briefly battle each other before accidentally merging into a hulking creature known as the Fury.

They are both considered for recruitment into the Justice League (sharing the identity of Firestorm with Ronnie being the brawn and Jason being the brains) along with several other heroes. They play a large part in the events leading up to the Trinity War, the three-way battle between the Justice League (the original headed by Batman, Wonder Woman and Superman), the Justice League of America (the A.R.G.U.S. sponsored team lead by Steve Trevor, Green Arrow and Amanda Waller), and Justice League Dark (the paranormal team consisting of John Constantine, Zatana and the Phantom Stranger). When Superman is framed for the death of Dr. Light and the League is taken into custody, Amanda Waller has Firestorm experiment on their ability to create certain elements: specifically, the mass production of kryptonite. It turns out that the two are indeed capable of using their powers to create it, but with some difficulty. However, this ultimately becomes moot once the Trinity War leads to the invasion of the Crime Syndicate, who supposedly kill off the Justice League. In fact, the League is trapped inside Firestorm by his Earth-3 counterpart, Deathstorm (a combination of Martin Stein and a corpse he experimented on), with only Batman and Catwoman escaping the initial fracas. The Leagues are presumed dead for a time, but are eventually freed from captivity after the Syndicate is defeated by Batman and Lex Luthor's Injustice League, Batman using Wonder Woman's Lasso of Truth to draw her and the others out of Firestorm.