Theo’s character undergoes an evolution throughout the movie. When we are first introduced to Theo, he is a depressed and hopeless coward, no longer involved in the rebels effort. He resistantly assists Julian in helping Kee get to the Human project. As Julian, and then Miriam die, he fills the role of Kee’s protector and leader.
He develops heroic characteristics and sacrifices his life for the survival of the human race. Cuaron chooses not to give Theo any weapons throughout the entire movie, nor does Theo show any interest for a weapon. He is not overwhelmingly handsome or well dressed, and he does not run towards danger but away from it. And in the end, Theo dies, without seeing the results of what he sacrificed his life for.
Cuaron dismantles all previous masculine heroic stereotypes illustrating Theo’s vulnerability and strength to carry on in the face of loss and death.