http://www.thedreamcastjunkyard.co.uk/2016/04/for-whom-bell-tolls.html I wrote an article, you should read it (and point out all my factual errors).
That's very informative! I like that he's continued The Justice Ray past the demise of the Thunder Force series. It's weirdly inspiring.
TFV does not have the ORN empire. It takes place on Earth, where humans found the wreckage of Rynex that drifted into the solar system. They build an AI called Guardian to reverse engineer the technology and build an army out of it for humanities interstellar expansion; Guardian then goes insane (?) and attacks humanity with its massed armada. TFVI then had the ORN empire attacking Earth, but it's best to not mention that game.
