Finale spoilersMore
He drives to Elliot and Gretchens, and kills them, shoots them cold blooded after hanging around and saying some badass **** about how they screwed him and created him("Heisenberg").
He then goes to Skyler, says some bad ass **** how he wanted to make things right but she kept getting in his way. Chokes her out. Puts ricin in a milk bottle and lovingly feeds it to Holly as he bobs her up and down in his arms, smiling at her, saying comforting things to her.
Walt Jr. walks in to see the massacre. Heisenberg emerges from hiding, snatches one of his crutches and knocks him out with it. Hits him a few more times to make sure he's dead.
The next scenes would play out just about the same-he uses the rest of the ricin to poison Lydia, makes his way to the Nazis, guns them down with the badass robot. He still saves Jesse, only to talk to him, telling him how if it weren't for Jesse none of this would have happened. He screwed up with Gus, he screwed up with the Pesticide operation, he's always screwed up and he always will.
They fight hand to hand and Heisenberg comes out on top(both are so weak at this point but Heisenberg is Heisenberg). Jesse's dying words are "**** you, Mr. White", to which he replies "My name is Heisenberg", and finishes him off.
He walks over to the lab, finds a batch of Blue Crystal, and starts smoking it. He keeps smoking and smoking, ****ed out of his mind, until he OD's. He dies foaming at the mouth. He finally did it, he finally broke bad.