Consider Firestorm as DC’s analog to the Human Torch from Marvel, but with some bonus atom manipulation thrown in. In addition, Firestorm is unique among superheroes in that he’s actually been almost always two people at once. Where one controls the body, the other, most often Professor Martin Stein, controls the mind as some kind of guiding voice.

This week The CW’s The Flash introduced Jax (played by Franz Drameh), an entirely new character to replace the deceased Ronnie Raymond (Robbie Amell). Jax’s background is an amalgamation of several who have lit up as Firestorm in the comics of DC. While we won’t see Firestorm again until Legends of Tomorrow premieres in January, dive into a super brief history into the revolving door of identities that is Firestorm.

Premiering in Firestorm: The Nuclear Man #1 in 1978, the first pair to become Firestorm was high school student Ronnie Raymond and Nobel prize-winner Professor Martin Stein. Ronnie was a new student and despite his natural athleticism, he just wanted to fit in. To impress a girl he has a crush on, Ronnie joins an anti-nuclear protest that turns violent. In an attempt to stop them, Ronnie gets caught in a blast, where he becomes fused with Professor Stein.

Because Stein was knocked out during the mishap, Ronnie’s body takes control when they become Firestorm while Stein acts as an inner voice during convergence. Stein also could not remember anything that happened while as Firestorm, which Ronnie kept a secret from him for a time.

In 1986, amidst the Cold War, the Firestorm series was taken over by a new writer, John Ostrander, who introduced timely themes and settings into the books. Stricken with cancer, Professor Stein wanted to leave a lasting legacy and called upon the United States and Russia to cease their nuclear arms race. Russia responded with a nuclear superhero of their own, Pozar. After the ensuing battle, Pozar — real name Mikhail Arkadin — was fused physically with Ronnie, but Martin Stein maintained consciousness over Mikhail’s body.

In 2004, DC resurrected the Firestorm books and introduced a new identity, Detroit teenager Jason Rusch. Desperate to get out of his impoverished life, Jason took up menial work for local thugs which led him to an encounter with the Firestorm Matrix, which was looking for a new host after Ronnie Raymond’s and Martin Stein’s (presumed) death after the 2004 crossover event Identity Crisis. After some time, Jason roped his childhood friend Mick Wong to become the other half of Firestorm, and together they were recruited to tackle a coming threat that would take place in DC’s 2006 crossover Infinite Crisis.

Following Infinite Crisis, Jason Rusch becomes the main possessor of the Firestorm Matrix while assisted by a telepath named Gehenna who becomes a love interest. But in the 2011 New 52 reboot, Ronnie Raymond is once again a high school football player while Jason Rusch is a classmate. During an attack on the school, Ronnie comes into possession of Professor Stein’s “God Particle” and transforms Jason and Ronnie into Firestorm.

This week on The Flash, Barry and the rest of Star LABS recruited aimless high school grad Jax to become the new half of Firestorm. With Ronnie Raymond dead, Professor Stein became weak and needed another to help bear the burden of the Firestorm Matrix. Jax, whose dreams of playing college football were crushed the night the nuclear accelerator exploded, now has a chance to achieve greatness. He’s entirely new to the DC Universe, never before seen in any comic book, so who knows what adventures and mishaps he (and Professor Stein) will find themselves in.