Goneril's relationship with Regan

Lear’s older daughters are largely indistinguishable in their villainy and spite. Goneril and Regan are clever—or at least clever enough to flatter their father in the play’s opening scene—and, early in the play, their bad behavior toward Lear seems matched by his own pride and temper. But any sympathy that the audience can muster for them evaporates quickly, (e.g. Act 2 - when they turn their father into the storm; Act 3: when they viciously put out Gloucester’s eyes). Goneril and Regan are personifications of evil—they have no conscience, only appetite. It is this greedy ambition that enables them to crush all opposition and make themselves mistresses of Britain. Ultimately, however, this same appetite brings about their undoing. Their desire for power is satisfied, but both harbor sexual desire for Edmund, which destroys their alliance and eventually leads them to destroy each other. Evil, the play suggests, inevitably turns in on itself.