Jack near-singlehandedly slays 3 giants throughout the movie. The first he killed by jabbing the giant's OWN knife into his spine, and when the giant backed into the wall, finished the job. He killed the next giant by putting bees in his helmet while he was near the edge of the giant realm, causing him to fall off, and he kills Fallon by throwing the last bean down his throat, which results in the beanstalk bursting out FROM INSIDE HIM!.
Elmont's fight with Roderick, which leads to Elmont nearly getting pushed to his death. However:
Roderick: Did you really think you were the hero of this story? Don't you know we all think that?
(he tries to stab Elmont's hand, but he takes the blade and stabs his own hand, which goes through Roderick's foot)
Elmont: I may not be the hero of this story, but at least I get to see the end of it!
Earlier in the fight, he was pushed underwater. He spots the knife he dropped earlier, grabs it in his mouth and then forces himself up, using the knife to slash Roderick across the face. Behold the reason Elmont became a Guardian; he pulls impossible stunts like this and makes them look more badass than they are in the imagination.
One has to give points to Fallon for his persistency. Despite falling into the fire moat and becoming scarred, he managed to swim through the aquaduct/sewer system underneath the castle and bursting through the floor to get at the princess.
The giants are breaking into the castle, and the guards are standing ready. The King is standing ready beside Elmont, and Elmont asks him to leave. The King's response? "Like hell!" And the King instantly became more badass than he already was.