Ronald "Ronnie" Raymond aka Firestorm is a former structural engineer for the S.T.A.R. Labs particle accelerator prior to its catastrophic accident. He is also the fiancé of Caitlin Snow, and is one half of the transmuted and conjoint meta-human, Firestorm.
Ronnie worked at S.T.A.R. Labs as the lead structural engineer of the particle accelerator. While working on the project in 2011, he became romantically involved with Caitlin Snow and in 2013 eventually got engaged to her. On December 11, 2013, Ronnie attended the S.T.A.R. Labs' particle accelerator's activation with his fiancée. The two talked about their honeymoon just prior the particle accelerator was turned on by Dr. Harrison Wells. When Cisco Ramon joked about how it was anticlimactic, Ronnie commented they would be in big trouble otherwise.
Just as the scientists of S.T.A.R. Labs started their celebrations, the gravity was temporarily removed, and they heard a loud bang. Discovering a chain reaction caused by an anomaly in the core chamber, Ronnie, despite Caitlin's objections, and Cisco went down to the core to shut the particle accelerator down manually. Before going into the core chamber by himself, Ronnie told Cisco to shut down the blast door if he was not back in two minutes. Cisco protested, saying he would not be able to reopen it, but was convinced after Ronnie pointed out everyone in the building would be dead if the blast was not contained. Inside, he adjusted the system so the explosion would go upward instead of outward, but was unable to make it back to the door until the two minute deadline.
Finding the blast door closed, he explained what he had done to Cisco over the radio, causing the other man to leave to reset the particle parameters to compensate. Caitlin, who had arrived at the core shortly before, begged Ronnie to find a way to get out, but he told her the door would have to stay closed to protect her. When the core exploded, he was presumed dead and his body vaporized.
Unbeknownst to his friends and family, the explosion merged Ronnie with Professor Martin Stein, via his F.I.R.E.S.T.O.R.M. project, and they became a meta-human. The merging vaporized Professor Stein's body, leaving nothing but a shadow mark, and reassembled Ronnie's body but it was Stein's mind who was dominant rather than Ronnie's. Out of concern Stein also wouldn't let either one of them see their respective beloveds though Ronnie was able to obtain control for certain moments.
The resulting mind meld caused Stein to refer to them collectively as "Firestorm." His abilities were witnessed by various people, and Firestorm was referred to as "the burning man" on Iris West's blog. Around ten months after the S.T.A.R. Labs accident, Firestorm was accosted under the freeway by two muggers who taunted the shivering Firestorm by asking him if he was cold. Getting up, Firestorm demonstrated his abilities by sprouting flames from his hands and head to scare off the muggers.
A few days before Christmas, Firestorm followed Caitlin 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 Firestorm with Cisco's help by following the ionized particles Firestorm emitted. When Caitlin tried to talk to him, he denied he was Ronnie Raymond and warned her to get away but Caitlin insisted they needed to take him to S.T.A.R. Labs to remind him of who he is, but Firestorm simply whispered their collective name and distracted Caitlin and Cisco with flames, and scaring the two scientists. That night, Firestorm arrived at the S.T.A.R. Labs just as the Flash was fighting the Reverse-Flash, and saved the former by shooting flames at the yellow speedster. When the Reverse-Flash escaped, Firestorm warned Caitlin not to look for him before flying off.
Firestorm approached Quentin Quale, a scientist and old friend of Prof. Stein's, looking for help, but lost control of his powers and burned Quale. Upon hearing this news, Team Flash decided to find and contain Firestorm. They interviewed Martin's wife, Clarissa, who told them that a disoriented Ronnie had come to her house a month after the particle accelerator accident, claiming to be her husband. Wells and Caitlin then staked out Clarissa's house, waiting for Firestorm to appear again. When he did, he was confronted by the Flash, whom he easily defeated by flying into the air. 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, Team Flash 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 Stein while preventing the explosion. Caitlin activated the splicer, but a huge blast of energy was released from Firestorm's body, engulfing the area.
The explosion, despite destroying everything nearby, separated the two and Ronnie was finally truly with his fiancée again. The two were brought back to S.T.A.R. Labs where Ronnie was reunited with Cisco and Dr. Wells, sorry to see him now confined to a wheelchair, and was given a fresh batch of clothes. Caitlin did some more tests on Ronnie as they also made out, much to Cisco's discomfort, but when Stein walked him he expressed his displeasure of being merged together for so long. Ronnie and Caitlin had drinks at CC Jitters and caught up with Caitlin's adventures with Barry and Team Flash in the past year.
However Ronnie proposed moving away but Caitlin was hesitant as she had formed new responsibilities now but Ronnie, though understanding, wanted away from the building that separated them for a year. Before they could discus the matter more General Wade Eiling's men attacked the bar to retrieve Ronnie but Flash came to his rescue, despite being pinned down with a special device from Eiling, Ronnie punched Eiling to distract him while he and Flash escaped in Caitlin's van. At the lab Stein told them that he felt everything Ronnie felt and after a brain test Caitlin confirmed their minds were still very much linked. To hide Ronnie, Barry let him stay at his house where Joe West, previously told of his demise, was surprised to see him but Iris also walked in and Caitlin made the excuse that Ronnie was his cousin "Sam." However Iris thought "Sam" looked familiar, unbeknownst at this point from his Firestorm appearances. Later Stein was captured and Caitlin ran tests to see if Ronnie could find Stein and after carving the word "where" on his arm.
Stein gave him morse code to follow to a military facility. Cisco gave Ronnie the quantum splicer as a means to keep them separated as Ronnie left with Flash to save Stein but when they came under fire, they were forced to merge but on Wells' advice rather than fight it they embraced it. Firestorm this time was Ronnie's body but both his and Stein's mind and they fought Eiling's men before confronting Eiling himself but he used a device to stun Firestorm and tried to execute him but Flash knocked him out saving Firestorm as they returned to S.T.A.R. Labs. While there Firestorm described the new process of merging and successfully de-merged back into Ronnie and Stein but because of the danger Eiling posed to both men decided they need to leave Central City. After Ronnie talked to everyone in Team Flash and kissed Caitlin goodbye, as Martin said goodbye to Clarissa, the two merged once more as Firestorm said "we love you" to Caitlin and Clarissa and flew off.
Later when Barry realized he was too slow for the Reverse-Flash he called Firestorm and Oliver Queen / The Arrow to help him in his upcoming fight against him. When Wells arrived at S.T.A.R. Labs to use the particle accelerator the Flash confronted him and Firestorm and Arrow son joined him, but Wells 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 used his tornado powers to send 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 defeated him Firestorm and Arrow parted ways with Flash.
Ronnie is a cheerful, carefree, protective and jolly individual. He will always look out for those he holds dear. Ronnie is also fun-loving, quick-witted and intelligent as he was the structural engineer for the S.T.A.R. Labs particle accelerator, but used to joke he was "just a high priced plumber". Ronnie and his fiancée Caitlin love each other very much; they complimented each other, Ronnie brought out Caitlin's compassionate, vivacious side. Ronnie showed complete selflessness in entering the particle accelerator and venting the particle accelerator explosion so to save Caitlin and his friends' lives when the pipeline exploded.
When merged with Martin Stein as Firestorm, Ronnie's being was kept dormant with Martin's personality in control, though he came to be in control sporadically and was always drawn to S.T.A.R. Labs and Caitlin, showing he never forgot about his fiancée. When they were separated, Ronnie and Martin were initially on bad terms due to Martin being in control of his body. Ronnie was overjoyed at being reunited with Caitlin and settled back in with his old life. Initially, Ronnie wanted he and Caitlin to leave for a new life somewhere else.
However when faced with the threat of Wade Eiling targeting Firestorm and seeing how his old friends and the world had changed, Ronnie adapted quickly. He displayed quick-thinking in using his link to Martin's mind to locate him when the latter was taken by Eiling and accepting the Firestorm Matrix with Martin, the two became friends in using their powers to help Barry fight off Eiling. Ronnie showed his ever selflessness in leaving Central City to protect his friends from Eiling, having said goodbye to Caitlin, but remained in love with her.
POWERS & ABILITIES
FIRESTORM MATRIX: When Ronnie merges with Professor Martin Stein, the two create the nuclear-powered composite being Firestorm.
ENERGY PROJECTION: Firestorm can project massive amounts of energy by projecting fiery nuclear blasts from his hands.
FLIGHT: Firestorm can soar through the sky at high speeds using jets of fire that he generates from his hands as propulsion.
PSYCHIC LINK: Ronnie can hear Martin Stein's disembodied voice while the two of them are merged into Firestorm. Even when they are separated, their link allows them limited communication of sensations or emotions.
EXPERT ENGINEER: Ronnie is an expert in engineering, as evidenced by the fact that he helped Harrison Wells build the particle accelerator.
BILINGUAL: Ronnie is capable of fluently speaking English and French.
IONIZED RADIATION: The Firestorm Matrix can be destabilized by bombarding its cellular structure with ionized radiation, temporarily disabling Firestorm's powers. Though it will not separate Ronnie and Stein it will cancel Firestorm's powers for a small amount of time.
SPEED VACUUM: When Ronnie was fighting Eobard Thawne, he made vacuums from his arms at super speed blowing Ronnie away.
This muse is character Ronnie Raymond from The Flash (TV Series)
Bio info taken from HERE