In my view, and it seems a lot of other fans' view, this is a game that, previous to Act 3, has benefitted from a cumulative nature, where there are more and more characters to interact with, and more repeatable elements to do and find. Act 3 seems to have gotten rid of a lot of that, and added a combat mechanism that doesn't really fit into the game. It would make more sense if:
1. The battles were the same sorts of typical VN-style interactions where we interact with someone new and use the same kind of maneuvering to gain control of them as in Act 2, leading to an Awaken or Shatter. We don't need the game to suddenly become something else entirely, especially at the loss of so much else that already works.
2. The actual environment were not changed so much, and could be quickly changed back to something like its Act 2 status with more to do. Add a construction element, maybe a new super-fast builder character, that rebuilds each part after each victory (maybe after being paid). Something more like when we go into the Nexus to turn Morgana's allies into ours.
Act 3 needs to fit in with the rest of the game better, gameplay-wise, theme-wise, and just storywise.