Cordelia is particularly striking, as she is on her own. She does seem to hold a different position, from the very start of the play, a position that is created by her father.
Lear sets up a game of manipulation; his daughters have to make a public gesture to show how much they love him. Cordelia observes the actions of her sisters, and says " if for I want that glib and oily art to speak and purpose not, since what I well intend, I’ll do ‘t before I speak". This implies that those who speak are using their words as art, but they do not necessarily match their deeds with these words. Cordelia says that she can say nothing because love cannot be spoken about. When she leaves she tells her sisters, ‘I know what you are, and like a sister am most loth to call your faults as they are named.’
I have tried to look at the dynamics between the initial scenes and Cordelia's return. Maybe because Cordelia is absent for so long, she feels she has to justify her return. She says that she has come back for her father, not just to gain land. Her return is not for political reasons. She seems to need to say that, to make it very clear.
Old king Lear banishes his good daughter, Cordelia, in his characteristic fit of anger, and it initiates the play's action. Cordelia's banishment is suggestive of the abandonment of reason in Lear and his impending madness.
Cordelia leaves her father with the king of France who seeks her in marriage. When, later in the play, Lear leaves his two evil daughters and appears on the heath in storm and rain, it is Cordelia who returns to rescue and console her father.
Further on, Cordelia dies just when Lear seems to have regained his sanity; she dies the death of a martyr; Cordelia is indeed a sort of Christ figure.