The Last Promise is an elaborate mod of Fire Emblem 7: Blazing Sword, casually referred to as just "Fire Emblem" in North America. The game hacks pretty much every concept that you could possibly think of--characters, classes, weapons, animations, graphics, maps, music, text, script, etc., you get the point. While this is no longer a big deal, when it was started many years ago, it was a relatively novel concept to mod many aspects of the game at once.