That's some mighty fine character animation right there. The action stuff was good, of course, but most imressive was the more subtle stuff near the end. Especially the last two camera rotations, on the face-off with the last skelleton and right after that when the ceiling started flashing.
Takes a lotta work to make that slow camera movement, animate the rotating characters frame by frame with only subtle pose-changes without any janky looking bits, and staying on model.
I think I noticed, those two last rotation bits had some tacticall corners cut though. With the last skelleton, you moved the camera positon so you only had to draw the character from the chest up. And at the final rotation you had some pilars move past the foreground during some trickier pose-changes. Thankfully making the workload on those parts a little less crazy, without looking like you cheaped out on the effort.