[ Mal lets him make his point because even if the Darkling does see him as a child, he holds himself with the maturity of a grown man at this moment, and it's only fair he lets the monster speak for himself. ]

You don't know what's best for Ravka or Grisha any more than I do. [ Mal believes he's been blinded by years of persecution and whatever loss he's talking about. And it's not as though Mal isn't sympathetic, to an extent, but it's hard to stay sympathetic towards someone who speaks to him like he's worthless. Frankly he has to hold back from spitting in the Grisha's face. ]

The path you've chosen will end with Ravka surrounded by nothing but darkness. Is that really what your people want? Or have you decided that for them? [ Mal thinks the latter since he has a history of deciding for others without their consent. ]

People are going to keep fighting you so long as they know there's a sun summoner who can finally get rid of what's haunted their lives. [ Mal included. ] And if Alina doesn't stop you, someone else will. She'll inspire others. [ She probably already has. ]

And maybe her getting rid of the Fold won't fix everyone's problems, but we need her light to bring back hope. [ That's what Alina represents, at least to him. He gets closer to the bars, close enough for him to be strangled by the Darkling's hands if he wants to try, but Mal has quick reflexes. He's a fighter, after all, and he looks the Grisha up and down, like he can't wait to watch his body burn one day, and for Alina to have been the one to set him ablaze. ]

I don't know how you survived - I don't care enough to ask - but make the most of your existence here because your days are numbered.

[ Famous last words. ]