Colonel Doctor Paul Church was a research scientist and a member of the United States Colonial Marine Corps. He was the son of Jason and Lucian Church. Church was the lead researcher on the Innominata space lab, operating under Admiral Thaves. Officially, his Xenomorph research was aimed at garnering a better understanding of the species' behavior and investigating the possibilities for controlling them, although he also derived several valuable biological and chemical technologies from the creatures, albeit through morally dubious experimentation.
While still a teenager, Church and the rest of the crew of the terraforming vessel Incunabulum — including his parents — were captured by the Xenomorphs on an uncolonized moon. Church subsequently spent 43 days imprisoned inside a Xenomorph Hive, where he was subjected to unspeakable horrors and was even impregnated with a Chestburster, although the creatures were killed by an unidentified fungal disease and Church escaped alive, removing the Chestburster from his own body himself. The incident deeply scarred him and largely influenced his later career as a research scientist specializing in the Xenomorph.
Paul was born in space to two terraformers and had never seen Earth until he was six. He spent much of his life on the Incunabulum with 8 other passengers, 9 if he counts Judith the Synth. Church was in love with Judith since he was 12 and even lost his virginity to the android, as one of her functions was keeping the crew sexually satisfied. He had also had a crush on Rebecca, but she never returned these feelings.
The ship was on it's way to RWL-1289, where the Clarks were to be dropped off, before the ship itself continued onwards. At the age of 19, Church had received a grant from the government towards being a scientist. He was also hoping to slip away and spend some time sharing secrets with Rebecca once they landed.
Inside the Hive
Church and a crew of other humans, including his father Jason and mother Lucian, land on an uncolonized world, but before they could begin their task, they were set upon by Xenomorphs. However, as they were dragged to the Farmed Hive, it became apparent that their captors were in dire straits. They had no Queen to oversee their colony, and a sickness lay heavily upon them, impeding their ability to breed.
After several days of suffering and watching his fellow crew members meet gruesome demises, Church was allowed to roam free around the hive so long as he did not prove to be a disruption. Following this experience, he began to study the species and plan a sabotage so he could escape. Church later refused to have sex with his mother, defying the Aliens' wishes for them to mate and produce more hosts. As punishment for this defiance, he was impregnated by a Facehugger, but when he awoke, he found that the rest of his crew and the remaining Xenomorphs had died. Even the Chestburster within him was too weak to emerge, and he learned that the creature was now rotting within him.
Church managed to make it back to the Incunabulum, the ship he arrived on, and scraped together enough surgical knowledge to remove the Chestburster himself, finding it was already dead. The surgery was a success, Church suffering no long-term ill effects afterwards. After sending a distress signal and being picked up, he learns that "Bug Farmers" were responsible for the Hive that had killed his crew.
The experience and knowledge Church gained from his ordeal was deemed most valuable. As compensation for his service for the government, he was granted a full biomechanical makeover and subsequently devoted himself to studying the Xenomorphs.
Church discovered, through a series of tests, that Xenomorphs will always attack a perceived threat over an unarmed one, and would rather engage an opponent than accept food, even if they are starving. They prefer food over a possible means of escape and, since they communicate telepathically, can see fear in prey which drives them to make particularly messy kills. Prey willing to fight back, however, causes them to pause and be wary. Set up on the Innominata space station, he pursued his research relentlessly. Among his experiments, he attempted to build an "improved" human race in his own image, with a collective hive mind similar to the Xenomorphs.
Church tricked fellow Col. Dr. Anthony Crespi into pursuing Lt. McGuinness into the Xenomorph pit, where he kept his pet alien, Trixie. Crespi was killed, but McGuinness escaped and found Church, badly damaging his face by slamming it into the metal railing at the edge of the pit then throwing him to his Alien below.
Later, from his hospital bed, a surviving Church observes the progress of Dr. Crespi, whom he now refers to affectionately as "Tony."
Personality and Traits
Church was, by all classification, insane. Despite an inauspicious youth, his experiences in the hive changed him for the worse, plummeting his mind into the depths of madness. Church believed that he was the most powerful human alive and considered himself a superior being. As a direct result, his value for human life was very low; he had no remaining respect for his fellow man and was treacherous and sadistic, as displayed when he set his pet Xenomorph on Crespi and McGuinness.