Before Brainiac's Invasion
At some point following the fall of Superman's regime, Jason Rusch was bonded with the Firestorm Matrix, discovering that if he combines with Martin Stein, he can become Firestorm. Wanting to become a superhero, Firestorm was contacted by Batman who wanted to recruit Rusch and Stein in his plan to fix the world in the wake of Superman's fall.
When Brainiac began invading the Earth, Rusch and Stein were assigned to protect Superman from anybody who might want to break him out along with the other new hero Blue Beetle. When Wonder Woman and Black Adam came to do just that for the good of the Earth, Firestorm and Blue Beetle managed to subdue them but, when the pair ultimately lost, Firestorm threatened to turn him into a nuke in order to prevent Superman's escape. However, Rusch was talked down by Batman, who conceded and agreed that Superman's release was for the good of the Earth.
Before going out to handle Brainiac's forces, Firestorm was asked by Batman to use his transmutation powers to synthesize gold kryptonite, a form of kryptonite that not only weakened Superman but made him as vulnerable as any human, which Firestorm complied.
Afterwards, while fighting Brainiac's invasion, Firestorm and Blue Beetle were captured and given to Gorilla Grodd to use as his telekinetic soldiers against the heroes that attempted to thwart his plan with Brainiac. While Blue Beetle remained with Grodd, Brainiac took Jason as a means of studying the Firestorm Matrix.
Now under Brainiac's control, Firestorm was one of the main enforcers guarding the interior of the Skill Ship, the other being Swamp-Thing. After the two are beaten by Superman and or Batman, the player's choice, Firestorm was returned to normal. 
Possible Post-Brainiac Epilogue
This section of history takes place in a timeline outside that of normal Injustice: Gods Among Us history. Information here does not reflect the true history of neither the Injustice: Gods Among Us universe nor the Injustice: The Regime universe, and should not be seen as relevant to future sequels or comic adaptations.
"The professor and me worked our tails off to control our powers. But Stein figured out the only way to beat Brainiac was to lose control."
"I correctly calculated that overheating Brainiac's engines would weaken him. But the quantum disruption we created caused an unexpected chain reaction ... the Skull Ship exploded ... and every city Brainiac stole from Earth was obliterated. Metropolis. Coast City. All of them."
"We thought we'd finally be the big heroes. The ones everyone looks up to."'
"But in our hubris, we lost sight of the hero's duty: protecting others at all costs."
"And we can't make that kind of mistake again."
"But still, if you ever need us, Batman,..."
"We'll be here."
- Firestorm Matrix
- Density Control: Elements tied to the Firestorm Matrix have 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.
- According to Damien's banter with Firestorm, Jason and Stein argue a lot.
- 2 Appearances of Jason Rusch (Injustice: The Regime)
- 4 Images featuring Jason Rusch (Injustice: The Regime)
- Quotations by or about Jason Rusch (Injustice: The Regime)
- Character Gallery: Jason Rusch (Injustice: The Regime)