Say my name

Declan: Who the hell are you?
Walter White: You know. You all know exactly who I am. Say my name.
Declan: Do what? I don't... I don't have a damn clue who the hell you are.
Walter White: Yeah, you do. I'm the cook. I'm the man who killed Gus Fring.
Declan: Bullshit. Cartel got Fring.
Walter White: Are you sure?
[Declan looks at Mike and Mike shakes his head]
Walter White: That's right. Now, say my name.
Declan: [quietly] Heisenberg.
Walter White: You're goddamn right.