Yassen was a child of circumstances. His parents loved him but was killed. The incident that killed his parents and all his friends, and almost killed him, was an act covered up by the Russian government.
Now he need to make it on his own. And the persons he met are not really good.
He was enslaved by a bad person for 4 years. Scorpia has attempted to kill this bad man, and freed Yassen in the process.
Now he worked for Scorpia.
He met Hunter, who saved his life.
Now we know Hunter is actually John Rider, Alex's father.
The story is interesting, but the details on who he met seems to be not that relevant to the story.
The ending is kind of dark and it actually gave some depth to how this boy became an assassin.
Quite good storytelling.