It is the responsibility of the OP to ask a clear, concise question
That, as of the writing of my answer, is a question run amok. Rather than improving the question, the OP simply appended... and appended... and appended... in massive quantities. Frankly, if you need to express that much information to ask a question, IMO you don't have a question (or haven't yet figured out what you're going to ask).
If you can't explain your backstory in three paragraphs...
Again, IMO, if an OP can't explain the backstory or premise of the question in three or fewer paragraphs (maybe add to it a 3-5 item bullet list of conditions or qualifications for an answer), then 95% of the time the OP hasn't figured out what they're trying to ask.
And no question on the main site should require more than a single sentence with a single question mark.
However, what to do when a question becomes incontinent?
1. Downvote
Please remember that a VTC is not a super-downvote. A VTC should only be cast if the question violates one of the appropriate-question rules. Ideally, it should never be cast because one doesn't like the question or because the question length/complexity is getting out of control.
2. Edit
Because ours is a creative site, we have a general unwritten policy to not substantially edit an OP's post save for legibility and/or grammar. This isn't the case on other sites. In fact, SE's general policy is that they encourage user B to edit user A's question if it clarifies the question without changing that question's intent. (That italicized bit is really important.)
In the case of the linked question, the question is way, way, way past the need for somebody editing it back down to proper size. Taking the time to do that helps the OP learn how to write better questions.
3. Live with it
If all else fails, because we live in an imperfect world, one can always live with the fact that some questions will be out of control. I suspect that for most of us, participation on this site is a hobby. Never let a hobby take over your life (or, said in the words of The Joker, "if you're good at something, never do it for free").