The Second Generation (第二世代, Dainisedai) are people, who have adapted to Spontaneous Human Combustion and were granted the ability to manipulate and control existing flames. and make familiars. As with the Third Generation, they sport higher physical capabilities as well as being more resilient to damage, along with natural immunity to flames.
Second Generations possess the ability to manipulate and extinguish flames. They can even manipulate the flames created by both the First and Third Generations, giving them a slight advantage in battles. Second Generations are known to be more skilled in the manipulation of flames compared to Third Generations. Second Generations such as Maki Oze have been noted to be an effective defence or counter-attack. It seems all Second Gens use their abilities differently in their own unique way, such as some simply turning flames into fire-balls, to some lowering the temperature of the flames to the point they convert it into ice. The abilities they use are unique and somewhat depict their personalities.
There are several types of Second Generations, one of which is Maki's long distance control of flames. When against a Third Generation, it's ideal to hide the fact that they're a Second Generation, in order to force their opponent into using their flames.
Maki's ability allows her to turn flames into sentient beings, which she dubbed "Pusu Pusu" and "Mera Mera". Her fireballs can be altered in size and shape or be merged into a single creature. Through such an ability, she can redirect fire attacks. Maki has also shown the ability to extinguish a large volume of flames in a single area, or redirect them to a different target.
Takehisa uses his ability through a pistol, which he has dubbed "Bullet Speed Control", that allows him to adjust the speed of his bullets. The bullets he launches can be made non-lethal. Takehisa can use the sparks, created by the bullets, to change the trajectory of his attacks. He can also ricochet his bullets, increasing their velocity and penetration force.
Karim's ability dubbed "Thermoacoustic Refrigeration", allows him to generate ice. Through his musical instrument, he collects heat energy inside, then transforms the heat into sound, thus decreasing its temperature, and by repeating the loop several times, creates ice, which can be launched at opponents or be used to incapacitate Flame Humans. In simplistic terms, Karim has compared his ability to how air conditioning functions.
Benimaru is both a Second and Third Generation, allowing him to use both abilities in conjunction with each other. After using his Ignition Ability to ignite his brigades matois, he can use his Second Generation ability to manipulate the matois similar to telekinesis. With his ignited matio's, he can use them for transportation or to synchronize the poles together to attack with.
Giovanni can use his mechanical hands as projectiles. He can launch them, extended by a long wire that can be heated and even burn through tree branches, and retract them. By using explosions to launch them, he can control the direction they go in. Giovanni has different type of projectiles. He's displayed using his regular hand as a weapon, a sort of grip-claw that can dig into objects, and electrical wires that can be used to electrify his opponents.
Charon can use his Second Generation ability to absorb and accumulate kinetic energy into his body from any attack, and transform it into thermal energy to attack with. Upon releasing it, the usage gives him the appearances of being a Third Generation.