"Brother, don't make me do this."
"No one makes us do anything."
"And you made our Father leave."
"No one makes Dad do anything. He is doing this to us." He wants to add 'all of us' because it's about Gabriel and Raphael as well but he can't say that because Gabriel's dead and he doesn't even know where Raphael is anymore.
"You're a monster, Lucifer."
But Dad still wants me. Dad wanted a devil.
"And I have to kill you."
No, you don't, of course you don't. You don't have to do anything, Michael. No one makes us do anything. Not anymore.
"If that's the way it's got to be then… I'd like to see you try."
And he wouldn't because he doesn't want to fight his brother. He doesn't want to kill another of his family but he will if he truly has to because God gave humans free will, but Father gave Luci free will too.