This theme only plays when fighting during bouts with bosses at the very end of each season of Elancia Chronicles: OoNG -- well, for the most part. Although it plays during the final fight during Seasons 1 and 2, during season 3, there is another theme for the final fight entirely, and the very final boss (of season 4) has a different theme, meaning that this particular one is played in an earlier fight. Extrapolation aside, rest assured, this is for fights against the biggest, baddest enemies that game will have to offer, and is set to the backdrop of some pretty startling story developments.