Nikko Bellic is being used as a Mcguffin device to keep the real Main Character out of the spotlight, The real main character is Roman Petronov, Nikkos cousin who invites him to live in Liberty after Nikko has a HUGE falling out with a paramilitary/Mafioso hybrid wing back in ESTONIA.
Back to 2007, Roman invites Nikko to the US with lies of his fancy living, just because he needed Nikkos help in dealing with shady characters trying to move into his little slice of heaven, which is a Taxi-Firm Roman works at on a co-operator term.
You WILL play the prologue missions as Nikko, to give you a hint of the new controllers, sadly, I dont know the schemes yet, but as soon as I do, you do.
Anyhow, about three quarters through the prologue, Nikko goes for his cousins associate " Mosha " to recover some drug money from one of the FOUR gangs in Liberty, a mainly South American gang modeled after the Columbian Cartels from GTA3, and the real life MS-13 gang, named " Carta ( Car Tuh ) Once ( Own-Said minus the D ) literally Card 11.
During this deal, Nikko gets murdered, and Roman ( Who was a great guy naturally, and never harmed a soul in his life ) becomes deeply depressed, because he feels responsible for Nikkos death, who was his only friend, and his guard dog in a brutal new world.
Armed with nothing but grief, and a deep hate for himself, Roman goes off the deep end, leaves his meager but honest job, and decides that in Liberty City, theres only one way out for a criminal AND a working man, and thats through the cemetery, so why die a shnook when you can die a rich man.