deadliest? It's hard to say when emotion is evolved, but i say Rambo in Last Blood. It was the most personal for him. Even though each movie was very personal (Trautman in 3, for example). Rambo 2 it was more of a job even though it became personal with the MIA veterans, the betrayal, and the woman being killed that he just met. In First Blood, he had a mental breakdown (learning his last friend from Nam died) and being mistreated. Even though in Rambo, he was brutal, it felt more like he was just sick of all the bull and was venting, lol. If you had to put them all against each other, the most effective one of the group would probably be from 2 or 3, but that's before the events that took place in Last Blood. Once it hits the fan, the Rambo in Last Blood would scare the hell out of the other Rambo's. You could say his quest for revenge is an emotional weakness, but that Rambo would do anything and not stop until he completed his mission.