Names and descriptions below may differ depending on the version of the game.
(Names are as follows: NA/JP/EU. However, some names in the EU version are the same as in the JP version.)
Before the meteor strike, there were two mega powers of the world. The two mega powers have been locked in a century of war where despite several amnesties, the war was never concluded.
- Lazuria / Sapphirus / Zephyria
- The sworn enemy of Rubinelle with whom they have been at war at for nearly a century. Commissioned the Strix Gun. Named after the blue gem sapphire.
- Rubinelle / Rubel / Laurentia
- Enemy of Lazuria, with whom they have been at war at for nearly a century. Seven percent of its gross domestic product was spent on new weaponry and its A grade army had 1,296,000 recruits at the country's peak. Named after the red gem ruby.
Following the aftermath of the meteor strike, there are four known faction remaining in the world.
- Lazurian Army/ Sapphirus Federation Army / Zephyrian Army
- Survivors from Lazuria, vastly fewer in number than their Rubinellen counterparts. The few surviving forces of the Lazurian Army are lead by 3 army commanders, indicating the unlikelihood that the leader of Lazuria survived. The Lazurian Army seeks to continue the war with Rubinelle; once defeated, the faction merges with the 12th Battalion when the latter aids in the Lazurian Army's escape from execution.
- New Rubinelle Army / New Rubel Armed Forces / New Laurentia Army
- Survivors from Rubinelle. Lead by the ruthless and power hungry Greyfield, they seek the destruction of the Lazurian Army. After the betrayal of the 12th Battalion, the New Rubinelle Army would stop at nothing in their quest for revenge. Their whereabouts are unknown after their failure to launch the Caulder Missiles.
- 12th Battalion / 12th Independence Company / 12th Independent Legion
- Rubinellen army personnel prior to the meteor strike; therefore their equipment and vehicles are identical to the New Rubinelle Army. The player's faction, they initially use their training and materiel to locate and aid as many survivors as possible, both military and civilian. As the game progresses, the affiliation, goals, and nature of the 12th Battalion changes to adapt to the successively greater problems they face. The 12th Battalion is noted for both its belief in humanity and its adherence to the rules of war in an otherwise lawless world.
- Intelligent Defense Systems (IDS)
- Private military contractor which also serves as a weapons researcher, developer, and supplier for all sides of the Rubinelle-Lazuria war. In the aftermath of the meteor strike the company is controlled entirely by Caulder and his family of clones. Caulder takes advantage of the world's devastation to carry out horrific experiments to satisfy his scientific curiosity, such as unleashing the Creeper on the world's populace to document the worldwide reaction to the disease.
There are 13 commanders who you will meet and face though story mode. With the exception of two, you will be able to unlock them all for use in free battle mode.
- The Beast / Vanda / Drakov
- Leader of a group of outlaws who view the world's destruction as a gift. Taking advantage of the fall of civilization, he leads his group in a spree of plunder and murder against whatever survivors they may find. Formerly a sergeant of the Rubinelle Army, expelled for his violent behaviour. The first primary antagonist of the game.
- Upon being shot in the leg by the 12th battalion, he receives medicine from Caulder. This treatment sends him into a rage of power that leads him to attack the 12th Battalion again and again in early missions. In his final battle he is fatally wounded by a 12th battalion soilder (it is suggested that Will/Ed shot him or ordered him to be shot but it is unclear). However, it is not the bullet that kills him; ultimately, it was the medicine given to him by Caulder, actually a poison, administered as part of another of Caulder's experiments.
12th Battalion / 12th Independent Legion
- Will / Ed
- The story's protagonist. Will (US) or Ed (EU & Japanese version) is a young cadet at the Rubinelle Military Academy as well as the sole survivor of its destruction in the meteor strike. He survived in the academy mess hall, sustaining himself on rations. When he finally manages to dig a way out, he is attacked by The Beast. He is then rescued by the 12th Battalion of which he later becomes a member. He sees Brenner as a role model.
- While searching for survivors, he discovers an amnesiac, Isabella, in the ruins of a city. Will develops a close relationship with Isabella and later saves her again on board of the Great Owl. He also discovers some of Caulder's horrific experiments, for which Isabella was intended to be used.
- Upon Brenner's death, he becomes commander of the 12th Battalion (the next-in-line after Brenner, Lin, stepped aside, as she cited her lack of charisma or ability to unite the now disparate elements of the 12th Battalion under one flag). He goes on to face the remaining antagonists of the game and is credited with bringing down Caulder once and for all.
- Brenner / Brown / O'Brian
- The initial leader of the 12th Battalion, believes deeply in the goodness of humanity and cares strongly about saving as many people as possible in the aftermath of the meteor strike. He is an honorable man and is respected by many. His death is caused by one of Caulder's inventions whist hiding in a destroyed city after buying time, forestalling the New Rubinelle Army, to allow for the escape of the Lazurian Army from their prison.
- The second in command of the 12th Battalion. Lin, unlike Brenner, does not have the same image of the goodness of humanity. She is a logical and formidable tactician but she has difficulty both with expressing her own emotions and reading and understanding the emotions of others.
- When Brenner dies, she was the next-in-line to be commander of the 12th Battalion. Instead, she steps aside for Will to become commander, as she lacked the charisma and ability to unite the disparate elements of the fragmenting 12th Battalion.
- She is later infected by the mutated Creeper Virus, at which point she asks Will if he wanted to leave her behind; Will characteristically refuses. She survives the infection after the final battle.
- Isabella / Cattleya / Catleia
- Discovered by Will in the ruins of a destroyed city with no memory, her given name is later revealed to be Lutaria. In truth one of Caulder's mass-produced clones used as lab rats. There were supposedly hundreds of copies of Isabella on the Great Owl. In spite of her amnesia, she has a vast amount of knowledge.
- She was infected with the original Creeper Virus which only affected young people. The 12th Battalion is later able to secure a military nuclear bunker possessing medical facilities, used by Dr. Morris to create a cure and vaccine for the original Creeper Virus.
- During the attack by the Great Owl on the 12th Battalion, Isabella was forced away by the civilians, led by the Mayor of Freehaven. She was taken aboard the Great Owl (where she was created) and would have died there were she not rescued by the 12th Battalion. Isabella is then able to convince Penny not to follow through with her orders to crash the Great Owl, killing all of the passengers. She survives Caulder's defeat.
Lazurian Army / Sapphirus Federation Army / Zephyrian Army
- Forsythe / Carlyle / Carter
- The highest-ranking (though retired) surviving commander of Lazuria. He is a skilled veteran and obeys the rules of war even after the meteor strike, refusing to use Caulder‘s weapons. He has a lot of respect for Brenner, having fought against Brenner's farther. Like Brenner, he believes in the goodness in humans and humanity.
- He surrenders himself and the remaining Lazurian Army once defeated by the 12th battalion. He is then shot unarmed by Waylon on Greyfield's orders. Brenner breaks with the New Rubinelle Army upon Forsythe's murder.
- Tasha / Atley / Zadia
- An air force commander that becomes second in command of the Lazurian Army after the meteor strike. She has a powerful bloodlust and is filled with hate for Rubinellens, as her brother was killed by Rubinellen soldiers before the meteor strike.
- After the assassination of Forsythe, she becomes the chief commander of the Lazurian Army, which then joins with the 12th Battalion after their escape from their prison/execution ground. She blames Brenner for Forsythe's assassination at first but changes her mind after Brenner sacrifices himself to save the Lazurian Army and 12th Battalion.
- Gage / Trak
- A consummate professional that specializes in long range attack. Terse and stoic, he suppresses his emotions and rarely expresses his opinions. His aim is to be the ideal soldier. Along with Tasha, he commands of the Lazurian Army after Forsythe's assassination.
New Rubinelle Army / New Rubel Armed Forces / New Laurentian Army
- Greyfield / Sigismund / Sigismundo
- The ambitious, power-hungry, and greedy leader of the New Rubinelle Army. Admiral Greyfield wants to make New Rubinelle the single power in a world united under him; to this end, he sees the devastation wrought by the meteor strike as a useful gift. It is said that in his youth he was a bully who falsified his own records to take credit for the work of others.
- Greyfield has a great dislike in the 12th Battalion and the Lazurian army. He works closely with Caulder and is happy to use whatever horrible equipment he comes up with. He ordered the assassination of Forsythe, an unarmed surrendered commander of the Lazurian army and also gave the order to fire a silo or Caulder Missile at the city Brenner was hiding in after the breakout of the Lazurian army.
- Greyfields also has little care for his men and solders who he is willing to simply throw away. He issues an order to kill any member of the New Rubinelle Army that have the Creeper virus as they are seen as 'weak'. This action causes uprising in the ranks of New Rubinelle Army which saved the 12th Battalion which they were fighting with at the time.
- Greyfields tries to launch a wave of Caulder Missiles that would have destroyed the 12th Battalion. He was stopped by the 12th Battalion who got to him in time and he was killed by Lin for revenge for killing of Brenner.
- Waylon / Dieter / Finn
- The mercenary for Greyfield. He killed the General of the Lazurian Army and destroyed Brenners tank. He was defeated by Will and also hates Lazuria.
- Davis / Cole
- Davis is a commander of the New Rubinelle Army who is rescued by the 12th Battalion. He asks Brenner, his previous friend, and the 12th Battalion to enter the war against Lazurian army. He is often shunned aside and ignored by the other New Rubinelle Army COs. After being infected by the Creeper Virus, he defects from the New Rubinelle Army and Greyfield's execution of all those with the virus. He joins the Fanatic's cult, although it is not known if he survived the virus at the end.
Intelligent Defense Systems (IDS)
- Caulder / Berith / Stolos
- The mad scientist that only seeks to learn. His HQ is the Nest and he was crazy due to he made the Creeper. He died after the Nest was destroyed. Claims to be a clone. He is interested in Will and his men and also wants Isebella for no reason. He wants a laboratory but has the other factions to experiment instead. His Creeper first targets the young kids but later on it targets adults. Sunlight of any kind can kill the virus.
- Tabitha / Lieselotte / Larissa
- A loyal daughter that plays with her foes a lot before destroying them. Also a clone. She was angry when her toy the Talon Gun was destroyed.
- Penny / Romy / Lili
- A young daughter of Caulder. Wants to play a lot and was the first one to test the first War Tank. Betrayed Caulder and survived unlike Cyrus and is a clone. Ordered to crash a plane to kill everyone but changed her mind because her teddy bear said no along with Issabella.
There characters appear only in the dialogue in story mode and help move the storyline along. They do not take full command of units on the battlefield.
- Mayor of Freehaven
- True name unknown. He is saved by Brenner and his 12th Battalion after the meteor strike. He is the mayor of the small village of Freehaven, a settlement of survivors. Although he pretends to care and act in the interest of others, he is a selfish man who only cares for himself and power. He tries many times to secure a higher position of power and to kick out the 12th Battalion.
- During one of the later mission at the end, he secretly forces Isabella away from the 12th Battalion and made her return to Caulder in exchange for their lives. He also selfishly accepts a sample of the 'vaccine' for the Creeper Virus from Caulder, which he paid for with his life. This was actually poison and was just another of Caulder's experiment.
- Dr. Morris / Dr. Moritz
- Before the meteor strike, he worked as a medical researcher in New Wolfington / Lotra City. Unlike the Mayor of Freehaven, he is the elected representative of the survivors and deeply cares about them. He is an optimistic fellow with a knack for puns, and often makes jokes even in dire circumstances - to the annoyance of the others sometimes. He becomes the expert on the Creeper Virus and is able to develop a temporary vaccine later on.
- The leader of a mystery cult which worships a mysterious entity known as 'The Worm'. He offers a magical cure for the Creeper Virus / Floral Virus to all who follow and worship the entity. He believes he is helping the people survive by telling them what they want to hear and false hope. 'The Worm' is revealed to be a mere earthworm (US Version) / fly (Europe Version).
- Cyrus / Cecil
- Cyrus is a genetic clone of Caulder and a commander in IDS. However, unlike his two sisters and farther, he recognizes the cruelty of his father's decisions and work ethics which kills people meaninglessly.
- He betrays Caulder and helps Ed and a few 12th Battalion to secretly board the Great Owl. The battle on board the bomber causes critical damage to the plane and thus is destroyed in a crash landing. For this, he is killed by Caulder but he manages to find Ed and the survivors of the crash landing. He makes Ed promise that he'll live in peace and directs the way to Caulder's HQ - The Nest.