The only thing that would accomplish that is the death of one of his children, IMO, whether it be caused directly or indirectly by Walt's new career
And in order for that to have any meaning, Walter has to still have real love for his children, something that "some" us thought no longer was the case.
I can't say I think he never loved his children, but I'm a firm believer that as much as he does love them, he loves himself more, or is so much more obsessed with himself, that he places his own needs & desires above theirs. (At least since the day he learned he had nothing else to lose) That is the worst transgression he's committing, while simultaneously bullshitting himself that he's done all this to help them
It's true that's there's little evidence to build a working knowledge of the man before his diagnosis, but between the back story, & the few scenes from the pilot, it's apparent he is a man who spent his adult life sacrificing to provide, swallowing his pride, & hating himself for who he was
Though he loves his family, in the beginning, it's apparent that he was a man that got very little joy
from his family. He was a man trapped in a family life, that deep down you could tell he resented. Finding out he'd be dead by 52 was the ticket to ride out his remaining days living any way he wanted, from trashing his boss's car wash, to beating down a kid who mocks his son
And it doesn't stop. He's lived that way ever since, choosing to play things in ways that benefit him over everyone else. I think the best thing about the scene where he lets Jane die is that you see those wheels turning, from the initial knee jerk reaction of panic that she might die, & he should help her, to considering that it benefits him better if she were to just die
He knows the right thing to do, by reflex, & is choosing to not do it. It's a new life of complete self interest, & when you're doing that, it reaps consequences on the ones who you claim to love
