He's a Russian Secret Service assassin working for Yuri Gretkov, a Russian oil magnate. Kirill always took his job seriously and was told to take out whoever he was instructed to, no further questions. He was just simply obeying orders by doing his job and getting paid loads of money for obeying his orders. It wasn't until after several months of disposing of Jason Bourne that Kirill was assigned a new target as Gretkov shown him a photograph of his next target

"This is who I want you to track down..", Gretkov said in a stern voice with a thick Russian accent, before sliding Kirill the picture across the table "Find them, but don't kill them.. Not yet. Maybe torture them a bit to get some information if you can. I'll give you the green light on when to kill them."

With that, Kirill silently nodded before setting off to find his new and current target