- This article is about the conjoint meta-human that is the result of the fusion between Ronnie Raymond and Martin Stein. For the individual characters, see Ronnie Raymond or Martin Stein. For the project, see F.I.R.E.S.T.O.R.M..
Firestorm is the name used by two transmuted men, Ronnie Raymond and Professor Martin Stein, together creating a nuclear-powered meta-human. Through transmutation, the two men were merged into one body, but with both streams of consciousness present. Initially Firestorm was Ronnie's body but controlled by Stein's mind, but Ronnie periodically took control for brief moments but the colliding men's minds also caused the firestorm matrix to become unstable towards the point of detonation. However thanks to a quantum splicer created by Eobard Thawne and Cisco Ramon, using parts from a Tachyon prototype, Firestorm was stabilized so Ronnie remained in control of his own body and Stein could still communicate with Ronnie acting as an adviser and co-pilot.
The conjoining was caused due to a mix between previously theoretical particles carrying Ronnie Raymond interacting with Professor Martin Stein, who held a scientific object, relating to his transmutation project, F.I.R.E.S.T.O.R.M., the namesake of the pairing. The quantum splicing that keeps Ronnie Raymond and Martin Stein together, and allows them to produce nuclear energy to use their meta-human powers, is referred to the Firestorm Matrix.
On December 11, 2013, Ronnie Raymond was caught in the blast caused by the S.T.A.R. Labs particle accelerator. He was transported along with many previously theoretical particles outside, meeting with Professor Martin Stein, who at the time held a mysterious object relating to his F.I.R.E.S.T.O.R.M. transmutation project. They were then merged in to one person, but due to their unwillingness, Stein's mind took control of Ronnie's body, while Ronnie's mind was suppressed, causing Stein to feel identifiably schizophrenic. With Stein in control, he tried to return to his former home to find his wife, Clarissa. However, due to his appearance as Ronnie Raymond, she didn't recognize him and attempted to call the police, before fleeing.
For the following 10 months, Stein chose to live under a bridge and scavenge through garbage to survive. He frequently began making use of his pyrokinetic powers, described as onlookers as a "burning man". One night, he was accosted by two muggers, who taunted him for appearing cold. He got up and displayed his powers, assuring that he wasn't cold.
A few days before Christmas, Firestorm, likely under the direction of Ronnie, followed Ronnie's fiancée, Caitlin Snow, to the Central City Mall garage. He approached her as she was getting into her car, but ran away when she noticed him. Caitlin caught up to Firestorm, but, unwilling to face her, he covered his hands and head in flames to scare her off and escaped the garage. Later, Caitlin found him with the help of Cisco Ramon by following the ionized particles Firestorm emitted. When Caitlin tried to talk to him, he denied that he was Ronnie Raymond and warned her to get away. Caitlin insisted the need to take him to S.T.A.R. Labs to remind him of his identity, causing him to take her face in his hands and whisper "Firestorm". He distracted the two of them with flames and promptly escaped. That night, Firestorm arrived outside S.T.A.R. Labs, right as The Flash was fighting the Reverse-Flash. He saved The Flash, shooting flames at the Reverse-Flash. When the Reverse-Flash escaped, Ronnie warned Caitlin not to look for him, before flying off by propelling himself with flames. Some months following, Stein approached Quentin Quale, an old friend of his. He claimed to be looking for help, but Quale hardly recognized him due to his new appearance, and he accidentally lost control of his powers, burning the physicist. Deciding to stake out Stein's wife's house, Dr. Wells and Caitlin waited for Firestorm to appear again. When he did, he was confronted by The Flash, whom he easily defeated by flying into the air and forcing him to drop. When Firestorm was about to strike down Barry, he saw Caitlin and fled. However, Barry had planted a tracking device on Firestorm and was able to find him again. With Clarissa's help, the team convinced Firestorm to go with them for treatment. Wells and Caitlin stabilized Firestorm's mind with a drug cocktail used for dissociative personality disorders. At this point, Stein's personality was dominant, with Ronnie's dormant, although Stein did have knowledge of Ronnie's memories and some of his feelings, including his love for Caitlin. When Wells discovered that Firestorm's body was destabilizing and would soon disintegrate in a massive nuclear explosion, Firestorm decided to isolate himself at a location far away from Central City to avoid harming anyone. Barry and Caitlin arrived with a quantum splicer, which they hoped would harmlessly separate Ronnie and Professor Stein while preventing the explosion. Caitlin activated the splicer, but a huge blast of energy was released from Firestorm's body, engulfing the area.
Fortunately, though creating a giant explosion, Ronnie and Professor Stein were separated, causing no nuclear residue. For a time, Professor Stein and Ronnie attempted to go their separate ways. However, they soon found themselves being connected and drawn back together. The S.T.A.R. Labs team was able to track down a kidnapped Stein, and in order to defeat General Eiling, Ronnie and Professor Stein decided to make peace with each other and willingly merge back together, giving Ronnie control but allowing Stein to have a voice within. Before Firestorm could knock Eiling down, however, he released an ion grenade, causing the Firestorm Matrix to destabilize momentarily and knock Ronnie down. As Eiling aimed a gun at Firestorm, The Flash quickly intercepted and knocked him to the ground. Initially about to hurt General Eiling, Barry suggested that they head home together, which Ronnie accepted. Back at S.T.A.R. Labs, Barry suggested that Stein and Ronnie try to separate. Trying hard, they were able to succeed. They headed back to Stein's home, where Ronnie and Martin bid their farewells to Caitlin and Clarissa, respectively, telling of their plan to go to Pittsburgh for more information on their condition. Outside, they merged back in to one, expressed their love and flew off.
Later when Barry realized he was too slow for the Reverse-Flash, who was really Dr. Wells but was also really Eobard Thawne impersonating the late doctor, he called Firestorm and Oliver Queen/Arrow to help him in his upcoming fight against him. When Eobard arrived at S.T.A.R. Labs to use the particle accelerator the Flash confronted him and Firestorm and Arrow soon joined him, but Eobard was unimpressed and fought all 3 of them. When Flash was down Firestorm distracted Reverse-Flash so Arrow could shoot him with a special arrow to disable his speed, but Reverse-Flash rotated his arm at super speed, sending Firestorm blocks away. Flash quickly recovered him and stopped him falling to his death and resumed the fight shooting a massive ball of fire at Reverse-Flash atop S.T.A.R. Labs when Flash lead him up there, causing him to fall on a car where Arrow finally finished him off with an arrow and made him pass out. Having succeeded Arrow and Firestorm left as Flash secured Reverse-Flash. 
When they first merged, they attempted to fight the merge, resulting in an unstable version of Firestorm, unable to control his powers. This version of Firestorm, as speculated by Eobard Thawne, formed a new organism choosing the more dominant parts for survival, in this case, Ronnie's youthful body with Martin Stein's more intellectual mind. As a result, this Firestorm was controlled by Martin but he could still feel Ronnie's subconscious. His personality however, was so unstable to the point he needed psychiatric medication for split personality disorder to keep his personality stable.
After merging properly, Ronnie and Martin were consciously communicating with each other and they were able to communicate properly with Ronnie apparently in control. It is possible they can switch controls. This version of Firestorm had perfect control over his powers and his personality was much more stable, no longer needing medication.
Powers and Abilities
- Nuclear physiology: Firestorm gets his powers from the nuclear energy his body creates. This energy is the source of his pyrokinetic powers. It can also be speculated that Firestorm could in fact transmute atomic bonds but has yet to demonstrate it.
- Plasma generation: As Firestorm, Ronnie can cover parts of his body in a fiery plasma He can deliver concussive blasts of flames from his hands.
- Fire Immunity: It can be presumed that with his plasma manipulation comes immunity to heat and fire
- Flight: Firestorm can generate enough propulsion from his hands to simulate flight and fly at high speeds. He can collide with objects and surfaces like a missile and cause an explosion by flying into them and be unharmed as his own energy shields him from the physical force he is exposed to, though only in his completely fiery state.
- Nuclear explosion: When Firestorm was separated by the tachyonic prototype, he caused a nuclear explosion that separated Ronnie and Stein. It is unknown if he can willingly cause an explosion of this magnitude.
- Expert engineer: Through Ronnie Raymond, Firestorm is an expert in engineering, as evidenced by the fact that he helped Eobard Thawne build the particle accelerator.
- Skilled in using Morse code: Through Martin Stein, Firestorm is familiar enough and able to construct Morse code messages without having to look it up.
- Multilingual: Through Ronnie and Martin, Firestorm is capable of fluently speaking English, French and Hebrew.
- Ionized radiation: The Firestorm Matrix can be destabilized by bombarding its cellular structure with ionized radiation, temporarily disabling Firestorm's powers and weakening him.
- Intense wind: While Firestorm is on fire, he is extremely vulnerable to sheer wind as exposed by Eobard Thawne.
- Quantum splicer: Originally the Tachyon prototype was used by Eobard Thawne to recharge his speed, he ultimately chose to turn it into a Quantum splicer to help separate Firestorm so they would not go nuclear. While the separation was successful it was found that the device could also be used to remerge the two into Firestorm should the need arise.
- The quantum splicer's shape (an abstract atom) is a reference to Firestorm's logo, worn on his chest in the DC comics.