Rex Chance is an ex-war correspondant and journalist, the son of Eric Chanikov and one of the main characters of the Impossible Creatures Campaign. His quest in the story is initially to reunite with his father, but he soon becomes embroiled in the confict revolving around the Sigma technology and the foreshadowing threat of Upton Julius.
When Rex was a baby, his father Dr. Chanikov took part in the first, and last, field test of a weapon known as the "Death Ray". As a result of his exposure to the radiation, Rex was imbued with countless animal-like abilities; he is essentially a combined creature. However, his unnamed mother was killed by the blast and a price was put on his father's head by the Russian government for the destruction caused by the weapon. For his own safety, Rex was sent to live in New York, (with his original surname Chanikov altered to Chance), while Chanikov himself took refuge in the isolated Isla Variatas islands.
Rex's early life is not explored, but what is known for certain is that he served during the Spanish Civil War as a correspondant and journalist until being fired in 1936. When fascists attacked the village Rex was in, he found a wounded soldier and instinctively helped him. This action cost him his job because, as he later explains to Lucy, "The first rule of journalism is you don't interfere". Rex did not seem to mind being sacked, though, as he disliked the chaos of the wars he had seen.
Rex's abilities seem to have disappeared during his time in America, as he shows all the signs of being a normal human being. It is safe to assume that they only manifest themselves while Rex is near Sigma technology.
Rex had lived his life under the belief that his father was dead, with a few newspaper clippings being his only source of information about him. On June 8th, 1937 he recieves a letter from his father, who says he wishes to tell Rex the truth about his past, and why he went into exile. The letter also provides coordinates to the island on which Chanikov's base is situated.
During the Campaign
Upon his arrival on Isla Undisonus, Rex does not get the greeting he was hoping for; there is no sign of his father anywhere, and he meets his first combined creatures. Upton Julius appears and reveals that he sent the creatures to capture Rex, the reason for which is unknown at this point. Lucy appears in her Lab just in time and rescues Rex, and from there on the struggle against Upton and his cronies begins. Lucy explains that Julius had captured Rex's father prior to his arrival and attempted to take her too, but does not know why.
Rex is able to apply the military strategies he learned from wars in combined creature battles. Between that and Lucy's extensive knowledge of the Sigma technology, they manage to win fights even when the odds are stacked against them. Since arriving on the islands, Rex also begins to develop his various abilities, even going so far as to control combined creatures without the aid of the Lab, which should be impossible.
Rex and Lucy soon travel back to Isla Undisonus and discover Chanikov has already been killed. Now fuelled by an intense sadness and a thirst for revenge, Rex aims to destroy Julius and his accomplices. Firstly, he and Lucy bring down Whitey Hooten and his men, and then set their sights on taking out Velika La Pette. On their travels towards Velika's island, they learn from the native villagers that she has been kidnapping their people and using them for experiments. After putting an end to Velika, Rex and Lucy chase down Otis Ganglion.
The villagers they meet on the way to Ganglion inform them that he has taken things even further than Velika; he has kidnapped villagers and attempted to combine them, which always resulted in their deaths. Rex and Lucy realise that the Sigma technology is too powerful, and that it must be destroyed. After defeating Ganglion, Lucy is captured by Julius and in retaliation, Rex forcibly hires Ganglion as an assistant. Through the deranged doctor, Rex learns the truth about his past, his abilities and Julius's plans; he intends to take over the world using combined creatures and the Sigma technology.
When they finally reach Upton Julius's island, Julius himself ambushes Rex and Ganglion returns to his side. Julius explains that Rex's extraordinary abilities are the final key to world domination, and he is so important because no other human being has ever survived being combined. He underestimates Rex's power, who is able to take control of his creatures and turn them against him. An intense battle ensues, with Rex's army fighting both Ganglion and Julius. The former is killed during the combat, and Julius is taken away by a creature (he is presumably eaten off-screen). Lucy emerges amidst the ruins of Julius's base unharmed, and is happily reunited with Rex.
Rex is generally kind and caring to his allies, but ruthless when it comes to enemies. He mentions that since he came to the islands, he feels much more aggressive and this is evident in the way he speaks to foes, often including threats or insults. As if to complement this, he can be somewhat stubborn and is ready to defend his opinions and ideals even against the likes of Lucy. Rex also harbors an overwhelming sadness because his only chance to meet his father was snatched away from him. He is distrusting of the Sigma Technology because of the incredible and bizarre feats it is capable of, and later due to the destruction it can cause.
In combat, Rex thinks with straightforward tactics that rely on overpowering the enemy with sheer force. His premade army in the game reflects his aggressive personality, with nearly all of his creatures being fast and dangerous in melee battles.
Rex's main task in-game is to collect DNA samples from wild animals and some objectives involve getting Rex to a certain location. Rex moves slightly faster than a Henchman, but can only swim after Mission 4 due to the cold waters. As a unit he is highly resilient, but the player will instantly lose the game if he dies; to prevent this, Rex can be garrisoned inside the Lab to protect him from harm and heal him if he is injured. Like Lucy, he does not count towards the player's population.
Throughout the Campaign, Rex gradually develops several abilities that he can use in combat.
Neuro Toxin - this "ability" is gained during Mission 4 after Rex revisits his father's Lab. It allows him to deal a very large amount of damage to a single enemy creature from a distance, but takes a whole 10 seconds to reload. Rex also cannot gather DNA samples while Neuro Toxin is reloading.
Regeneration - Rex develops this ability near the beginning of Mission 7. Rex's rate of healing is 4 points per second, which is much faster than that of other combined creatures.
Control over combined creatures - This does not affect gameplay, but Lucy mentions that her Lab is normally what allows them to control their creatures. When it is damaged during Mission 9 she realises that Rex is in fact controlling them directly. This particular ability is so developed that Rex can even control the "goliaths" in Mission 13.
During the final cutscene when Rex hugs Lucy, his eyes become a solid white without any pupils. This trait is shared with wild animals and combined creatures.
Despite his abilities not appearing until arriving on the islands, Rex mentions that he was once bitten by a dog which then became sick as a result of his Poison Touch.
In Player Vs Computer Rex Chance/The Hero's Army Has Cheetah/Porcupine' Poison Frog/Ram' Crocodile/ Mountain Lion' Snowy Owl/Panther' Piranha/Lioness' Bull/Hornet' Bull/Baboon' Rhino/Cheetah And Sperm Whale/Lobster.