Grandiose sense of self:
Walt believed he was intellectually superior to almost everyone around him. He couldn't tolerate being treated as ordinary.
Extreme need for recognition:
Making money wasn't enough. He needed people to know that he was Heisenberg, the brilliant mind behind everything.
Manipulation:
He repeatedly exploited Jesse's emotional vulnerabilities, using guilt, affection, and fear to maintain control.
Lack of empathy:
As the series progressed, he became increasingly willing to sacrifice other people's well-being to protect his interests.
Fragile ego:
Walt reacted intensely when his intelligence, authority, or accomplishments were questioned. His pride regularly overpowered his judgment.
Sense of entitlement:
He believed his suffering, sacrifices, and intelligence justified actions that would be unacceptable for anyone else.
And possibly the biggest giveaway:
"I did it for me. I liked it. I was good at it. And I was really... I was alive."