The fact that George decides to investigate the mystery all by himself after his near-death experiences - whether the cafe explosion, kidnapping or being chased by henchmen.
In the first game, When George's head is hit by a wooden salmon and loses conciousness, Nico shows up from the rooftop and manages to kick Flap and Guido to get the tripod. Even George is impressed after that.
How about in the second game where Nico saves George at the pyramid before he becomes Tezcatlipoca's sacrifice?
In the third game, after George receives the Psi stone the Preceptor says he'll send his best knight. The Preceptor calls one of the Templars to bring a long wooden case. George realizes that the Preceptor holds the sword and tells him to kneel. For a man who experiences a lot of adventures, George finally deserves being a knight.
Nico's response when she and George encounter Petra near the end of the third game.
Nico: "George, you'll deal with the Grand Master. I'll deal with this bitch!"
Brother Mark, Archie and Spallaci's Big Damn Heroes moment in the fourth game.