Tomas Sevchenko, or Sev for short, is the main protagonist of Killzone 2 and Killzone 3 and is the main playable character of both games. He is a soldier of the Interplanetary Strategic Alliance and is a skilled technician which makes up for his shorter war experience as a new comer.
Sev was born in Northern Vekta in a solid and respectful family. Seeking to defend his homeland, Sev joined the army despite opposition from his parents and fought during the Helghast Invasion of Vekta. He had powerful idealism and managed to repel the Helghast invaders and take up arms again however he was scarred by nightmares of the invasion. He was eventually signed to Alpha Squad during the ISA Invasion of Helghan in 2359.
Events of Killzone 2
During the events of Killzone 2, Sev was assigned to Alpha Squad and landed on the shores of Pyyhrus during the invasion. He and his squad made it to the Corinth River and began to advance as Helghast soldiers opened fired and slaughtered all ISA soldiers in their sights and managed to thin out Helghast Resistance.