hey! sorry for the delayed response. the final battle is a common point of confusion, i should probably write a boss guide just to be safe. there are a few pieces to the puzzle, but it sounds like the one you're missing is that you need to use Strike Formation to draw Concourse into the fray. it might take some persistence, but you can finish her off while she's building FV to set WHEEL back in motion. also, this might not be necessary to mention, but there's an optional item hidden behind a gold door that can make the fight a little easier, too
thanks a lot for playing & for sharing such kind words, and good luck with the last stretch! i'm here if you have any other questions (i'll make sure to respond promptly)