Firestorm is a superhero with nuclear abilities. He is voiced by P. J. Byrne.
Once two ordinary individuals Professor Martin Stein and high school student Ronnie Raymond were brought together by the twisted hands of fate. A terrorist group attack a nuclear power plant and held Professor Martin Stein as a prisoner, demanding to build them a weapon. Ronnie (who was on a field trip) was taken as a hostage. The terrorists then threw a grenade at the nuclear engine that Stein was working on, causing a strange phenomenon. Both Ronnie and Martin merged together to create a being of nuclear energy. Together they could manipulate matter at an atomic scale and radiation, become the atomic man Firestorm. After saving the state from the runaway Nuclear Family, Firestorm was met by Superman, Wonder Woman, and Batman with the offer of joining the Justice League, which he accepted. Firestorm has a crush on Killer Frost but in a way she likes him back as well.
- Density Control: Firestrom has complete control over molecules and as such can change the density of solids, liquids and gases to as light as hydrogen or as heavy as uranium.
- Eidetic Memory: Also called "Matrix Memory Recall", elements tied to the Firestorm Matrix can access the memories of each and every single being that has ever been fused into the Matrix. New elements are allowed to automatically download surface information.
- Energy Absorption: Elements tied to the Firestorm Matrix can absorb massive amounts of energy as well as being able to absorb many different types of energy. Most commonly the elements and energies associate with life and the human body are absorbed. Also solar energy is a possible source of energy that can work as a "emergency battery" for elements out of power.
- Energy Projection: Elements tied to the Firestorm Matrix can project massive amounts of different amount of energies. Naturally occurring energy projected by Firestorm are "Nuclear Blasts" however elements can project a number of different energies at will.
- Enhanced Vision: Also called "Quark Vision", elements tied to the Firestorm Matrix have access to enhanced vision due to their nuclear nature. Different visions experienced are X-Ray Vision, Microscopic Vision, and Thermal Vision.
- Flight: Elements tied to the Firestorm Matrix can soar through the sky at amazing speeds. At first it may be difficult to achieve flight through Firestorm's nuclear nature though most master it quickly. Firestorms have been clocked at over 600mph theoretically they can fly much faster.
- Molecular Reconstruction Elements tied together into the Firestorm Matrix to create Firestorm have one main ability which all other stem from. Their "atomic fusion" or "nuclear nature" stem from nuclear physics tempering with the user's mixture of psychic energies as well as physical properties. Users accessing Firestorm or the Firestorm Matrix are called "elements" as they individually make up the Matrix. Firestorms can break down and reapply subatomic particles as well as break up the molecular structure of elements and rearrange them. To do this the element must know the exact elemental make-up of the object or human. Most Firestorms cannot affect living tissue but it is possible though very unstable.
- Phasing: Elements tied to the Firestorm Matrix can phase their bodies through solid objects. Although they have direct control over an object's density they can use this ability on themselves and only themselves and affect living tissue to pass through objects.
- Psychic Link: Sometimes called "floating heads", elements that embody the Firestorm Matrix appear mostly as floating heads to represent their psychic link to the other human being or other element in the Matrix. They can be represented however they'd like but the Matrix defaults them to a disembodied head. Even disconnected an element may have latent psychic traces of the previous user.
- Regeneration: Though a majorly untested power as well as being as much a reaction from shape-shifting and a direct result of molecular reconstruction; nonetheless, Firestorm elements can regenerate large sections of misplaced or destroyed physical properties.
- Self-Sustenance: Elements tied to the Firestorm Matrix can survive in space unaided, never need to eat to sustain life and never truly need another element to be processed or broken down by their bodies. Although users may feel these needs and would enjoy producing such bodily functions it is unnecessary.
- Superhuman Durability Elements tied to the Firestorm Matrix receive an increased amount of physical resistance and durability. They can survive bullets and stab wounds as well as the physical damage of exploding constantly.
- Superhuman Strength Elements tied to the Firestorm Matrix receive an increased amount of physical strength and muscle mass. Certain elements can tap into this energy and become large hulking entities however such strength can be quite destructive to the host if not used sparingly.
- Transformation Elements tied to the Firestorm Matrix can transform from their "normal" human forms into Firestorm, the Nuclear Man. However other entities may take whatever form they want; such as, Black Lantern Firestorm and Fury. Furthermore, elements can transform their body or body parts at will with concentration with an unknown level of restraint.
- Nuclear Family Values
- Freezer Burn
- Field Trip
- Double Cross
- Garden of Evil
- Mxy's Mix-Up
- The Cube Root
- Forget Me Not
- Race Against Crime (non-speaking appearance)