Finally decided to go back and do the challenge battles. Most of them are entirely forgettable, with a couple of waves of nondescript enemies. Only the 5-star challenge battles pose any real challenge, and in reality it's more like 2 in particular (Four Devas and Heroes Frontline). These two require a complete understanding of the combat system and how to build your characters (which nothing in the base game ever really pushed you to do), and were the most enjoyable part of the challenge mode. You also get swimsuit costumes for beating them which were whatever. Definitely a downgrade from XC2's challenge mode.

The new hero Ino was also pretty disappointing. Her exclusive Inoswap feature was pretty much just a glorified soul tree that requires collecting a new type of ether found in the overworld. Her class is also pretty bad, although the concept of a tank becoming stronger as they die more could be interesting if it was actually done well.