I think both are important, but the central idea might have a stronger impact. It's the core concept that everything else builds upon.
In my opinion, theme is more applicable. A theme runs through the entire story and gives it a deeper meaning.
Chapter 219, ", Purge Action", is the clearest early answer because it turns Demon Hunter Squad's situation into a concrete plot event. Early on, They simply abducted him and then hurried nonstop to Beigu City.. By the end, That included the tragedy of the veteran..
Chapter 201, ", Maritime Relics", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. The setup is There has been a correction to the last chapter; the arrangement in..., but the pressure keeps building through The comments weren't deleted, but after the content was changed, all....
Chapter 269, ", The West Coast of the Continent", is the clearest early answer because it turns Alliance's situation into a concrete plot event. The chapter gives readers a real answer by opening on Regarding the increase in death penalties, Gu Hang was somewhat... and ending on Now, with the sudden replacement by public servants cultivated by the....
Chapter 354, ", Meritorious Unit", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. The setup is Is it still not time?" General Hans was somewhat angry., but the pressure keeps building through Then just when do we have to wait?.
Chapter 276, ", Intercontinental Missile", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. It opens with The Alliance isn't Gu Hang's alone; he can't make all the decisions... and closes on All of these could be seen without even needing to enter Blackbird.... The key payoff is that the chapter closes with Gu Hang rejected the guard's suggestion and immediately left the office.
Chapter 332, "The Titan is completely finished", is the clearest early answer because it turns Knight Titan's situation into a concrete plot event. Early on, The Phoenix Battle Group had been a part of this battle right from.... By the end, The time between their destruction was just a mere eight minutes....
Chapter 378, ", Star Language Phone Call", is the clearest early answer because it turns Star Speaker's situation into a concrete plot event. The chapter gives readers a real answer by opening on The original Star Speaker from Rage Owl Star couldn't do it. and ending on The next time he called Wuji Star, it should only take an hour to....
Chapter 364, ", Golden Light Enters the Dream", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. It opens with The power of subspace is infinite, and subspace is "generous". and closes on It was as if a bucket of cold water had been poured directly over his....
Chapter 238, ", 'Unique' Upgrade Sequence Unlocked", is the clearest early answer because Gu Hang finally turns buildup into a real advancement. It opens with However, what Gu Hang was looking at right now was not these signs. and closes on The remaining power of that entity wasn't much, but its status was.... The key payoff is that it turns exploration's growth into a concrete upgrade step and sets up the next payoff in the power growth storyline linked to Unique.
Chapter 290, ", Western Desert Campaign Settlement", is the clearest early answer because it turns Colonel Li Kexi's situation into a concrete plot event. The setup is Colonel Li Kexi certainly had reasons to be angry., but the pressure keeps building through Although the Beast Slaughter Brigade had replenished its soldiers,....