What I don't get is that in the beginning of season six we see Tony barely survive a gun shot wound in the stomach after being in a coma only to be killed at the end.
He was basically given a second chance, by surviving nearly the impossible, basically given a second chance to reform, change, etc. But he didn't, and in doing so, pissed away his second chance/redemption and sealed his fate.
It's like Vincent in Pulp Fiction. Jules believes that them surviving being shot was a miracle, divine inspiration from God basically a warning, and retires from the gangster life. Vincent doesn't, dismisses God, fate all as chance or luck, stays in the game and gets killed within two days after by Butch.
