Turn A was originally supposed to be followed up by a sequel. Turn A Space was a name thrown around and so was Turn A Galia Senki.

Some ideas I had was Guin fleeing to Garia to start another industrial revolution, leading into another war or a cosmic horror coming from beyond the solar system to reclaim the Turn X in the style of awakening of the trailblazer.

maybe someone digs out the ∀ and X from their cocoon and it metamorphisized into a new Turn Unit and they go crazy from the power.