She was a legend - she'd saved the Avatar as he saved the world. She was respected and feared, but few could love the Waterbender who had broken her people's most sacred traditions in order to do what needed to be done. Too many feared that, having once turned her healing gifts towards harm, having stood over another human being, even one as demonic as Princess Azula, and calmly watched her writhe in agony as all the water left her body and she died desiccated and in pain, that the Waterbender might have acquired a taste for it. If she decided to do it again there was no one could stop her, and so she was feared.
He was a legend - he'd stepped up after the Avatar had won and had taken charge, refusing to allow the fragile balance of the world to be further disturbed by revenge. Neither the Earth Kingdom nor the Fire Nation were allowed to destroy the other, and his knowledge of both meant that he could accomplish the feat without inciting hatred. It had even become a fashion for people to paint the symbol of their country over their left eye, a stylized tribute to a man once reviled by almost everyone. He had worked hard to learn to speak with kindness, and so he was admired.
Their love was not a legend - it was private, almost secret. It had been so well hidden, in fact, that neither of them knew of it for a long time. She had taken to visiting him often, because the Fire Nation was used to cruelty from their superiors, and hardly anyone made signs for protection from evil as she passed; she could almost feel normal for a little while. He looked forward to her visits, because he could speak without being careful and know that she, at least, wouldn't cringe away from the harshness that he was so diligent not to show anymore, and he could almost feel like himself when she responded tartly to whatever he said. Comfortable with each other, they might have continued as they were indefinitely if not for a single kiss among the hundreds exchanged by friends and strangers alike as a festival tradition. Some talked about the results in terms of the necessity for the succession, and others about the need for cementing diplomatic ties between Fire and Water, but only a few who were themselves legendary understood the truth, that love is stronger than legends.