Sephiroth (TFE)

Sephiroth is an antagonist in the Final Emblem Saga, and is a non-playable character. He has a character-specific class unique to himself, Fallen Seraph. Sephiroth is not normally fought until the final chapter (though he is not the final boss), but there is a chance of encountering him in an Arena battle as early as Chapter 1. However, it is not even possible to defeat him at all until either the next-to-final chapter, or the player has had Syaoran, Levin, Aira, Eve or Train level grind to LV40, promote, and then level grind to at LEAST LV50.