This is much better, clearer, and more emotionally appealing then the last one you had put up. I'm intrigued to know how he becomes immortal though, wander if there is a way that can be added in, or would that give too much away? I would also end the log line as if you are still telling the story as opposed to saying 'in a tale of...' I would personally say 'becomes an immortal assassin and sets off to seek horrifying revenge.' Or something like that.
Overall though much better than before and has now become less generic and asks more important questions.