Pavel Arkhangelsky was born on February 13, 2006 in a hospital somewhere in Japan. His parents lived in the Soviet Union before its collapse. Afterwards, they moved to Japan due to programs that paid relatively well for their technical expertise in engineering. He was enrolled in a local high school, where he met Sayori, who was somewhat sympathetic to his cause. Indoctrination was wasted on him as he had learned Soviet patriotism from his parents from a young age.
Despite his best efforts, Pavel was never more than an average student, in part due to his alienation from his classmates who were complete slaves to capitalist ideology. For his first year, Sayori was his only friend. Though he attempted to join a socialist club, it was full of demsocs and he left angrily.
The following year he was invited by Sayori into the newly-formed literature club, which, under his guidance, became a sort of hub for socialist activities. This culminated in his invitation to Hope's Peak Academy as the Ultimate Marxist Leninist.
Unaware of what was going on at the time, he was thrust into the Killing Game. Though thrown off his footing at first, he was able to gain the trust of the remaining students and used his limited knowledge to construct simple devices such as molotovs and even a rudimentary cannon. Eventually, he was able to escape Hope's Peak Academy.
In March of 2029, when the duties of reorganizing post-verzwieflungkrieg society was at last completed, he married Sayori in Leningrad. Three years following, they had their eldest child, Kiril. Seven years following, another child, again a son named Milorad.
In terms of personality, on the chart thingy I made the fuck up, he can best be described as warm/passion. He obviously cares about his friends, and also excels at political agitation.