How better to sell this whole hero thing to a potential newcomer than by referencing the death of the man who last held the moniker that youre offering him? Thats exactly what happens when Caitlin reveals to Jax that her husband, Ronnie Raymond, was the last person to be part of Firestorm with Dr. Stein and that it was him who lost his life protecting Central City. Sure, it serves as selling the opportunity to become a hero and to help the greater good, but its still essentially highlighting to this unsure newcomer that the gig you want him to fill is one that took the life of the last person to take it on.