How fitting. Sun and Luna were banished by beings even higher than them because they couldn't understand and/or adapt to the concept of bonds and it's strength. And now, they'll be banished by those they created because they fail to learn from their previous mistake regarding that same concept, which for humanity takes the form of love. Truly fitting, especially if their defeat ends with the two of them isolated from everything except for one another, since that'll probably be the only way for the two of them to learn, as I doubt with the way things currently stand, Sun and Luna even understand themselves let alone each other.