The Secret Final Boss battle was truly one of the most epic fights I've had in a JRPG. It wasn't nearly as difficult as some people on the Octopath message board made it seem but it was in every sense of the word, epic.
That build-up and having to use all 8 Travelers to go up against Galdera, with all that foreshadowing in each of the Traveler's tale made the battle all the more exciting. I liked how the two forms mixed it up so that strategy was vital to survival and gave you a sense of going truly all-out without holding absolutely anything back. And also, that OST, holy **** it was awesome and befitting of a Final Battle.
I'm throughly impressed by what the game has put up throughout and really look forward to games of similar nature in the future.
Easily the 2nd best game of the year behind only God of War and a must play for every fan of the genre.