Gerald, in all basis, is a Nazi loyalist, who seeks to restore the Third Reich and has obsession on his Fuhrer, Adolf Hitler. He was part of the Pseudo scientific research organization, Ahnenerbe, and is extremely eager to find anything to help his goal of restoring the Reich. 

He is shown many times of being an incredibly violent individual, who cares little for the lives of others. This is shown when he told Lambert to kill Laetitia for finding out what their up to and that they have no use for her anymore. He even attempt to kill her by throwing her unconscious body out of the plane if Lambert does not do what he says. He also seems to care little of his men as he allowed them to die for his needs to find the eclipse and does not even acknowledge their efforts in helping him,