In this case the narrative arc revolves around a character arc, that of World-Ender. As such, I’ll be describing both the events and World-Enders feelings, personality and motivations at the time.
1) Exposition:
Article Iteration 1: The Foundation notices mentions of ‘World-Ender’ appearing in SCP documents, anomaly generated narratives and other Foundation-related stuff. In all cases these alterations feature ‘World-Ender’ causing doomsday. As such, the Foundation designates these appearances as an] ‘pending’ anomaly. These appearances are actually the result of ‘World-Ender’ appearing in multiple narratives within narratives, with the larger narrative being the Foundation universe, after crossing over using SCP-1985, who appeared in his last world after a test with her and SCP-423. One of the places ‘World-Ender’ appears is a SCP-3922 affected narrative, in which he defeats the agents but not before they recognize him (they’ve had experience with him in the past) and warn the Foundation.
2) Rising action
Article iteration 2: The Foundation finally figures out what ‘World-Ender’ is, a pataphysical entity that is an embodiment of villainy, specifically world-enders. They document several instances of him ending fictional worlds, usually in ways he feels are ‘ironic’, ‘fitting’, ‘poetic’, showcase his own resourcefulness and ingenuity or create what he believes is ‘a better narrative’. An interview utilizing SCP-423 helps show World-Enders personality, simultaneously feeling that ending worlds is his purpose, job and simply who he is. He says that he believes that causing doomsdays is his ‘art’, creating ‘masterpieces’ in the world he destroys so that ‘people higher up can enjoy them’. He believes that stories in which the world ends are superior to others, as they showcase tragedy, struggle and many other emotions, which he believes makes them more compelling than other narratives. Importantly to the Foundation, he claims that he is planning on ending their world, though he claims this is ‘nothing personal, just the way it is’. He lets Fred leave because ‘no-one cares what happens to the background characters’.
Article iteration 3: Following this, the Foundation makes continual attempts to contain him. While he initially finds this a fun challenge, he soon gets tired and frustrate, claiming that it’s ‘usually not this hard to destroy a narrative’ and asking the Foundation to ‘let him do his job’. Eventually he starts to hold a specific grudge against the Foundation, starting to destroy worlds in ways that mock the Foundation, deliberately falling into their traps into to bust out easily, becoming more and more brutal with their pataphysical agents and becoming extremely blunt and direct with his methods, all with the intention of frightening and disturbing the Foundation and making them feel powerless. In a follow-up interview utilizing Agent Barker he insults the Foundation, claiming that they are ruining his purpose and art and that his ‘new art’ is focused on justifying that affront. It is clear at this point that the Foundation’s actions have cause him to fall into a state of rage, with Agent Barker barely escaping with her life.
3) Climax
Article iteration 4: Oh no! Someone put a book containing World-Ender into SCP-826! He’s Apollyon now and we’re all going to die! But not really. It’s just him manipulating the SCP file. But suddenly the file mentions a glyph appearing on the ground, which World-Ender steps on and vanishes.
One thing to note is that while reading the article, there have been notifications at the top of the screen. ‘You are viewing file iteration 3/5’ and such, standard stuff. But suddenly that notification appears halfway through the file, and you realize that it’s not a computer notification but active narration of what you are doing. Then it says that your computer is rumbling. Turns out, you’ve rigged your computer with one of those narrative extraction widgets and now World-Ender is in your world! Oh no again!
Except, after killing you, World-Ender looks around and finds nothing but a featureless room. He initially expresses confusion, but then realizes that he’s in yet another narrative, which you positioned above a narrative he was already in while he was changing it. And he can’t escape, because the setting only feature him and you, and unnamed protagonist, with all of the details, characters and setting being documented a narrative layer below, which you just tricked him out of. Shocked and desperate, he accesses the final iteration on the fictional computer.
4) Falling action
Article Iteration 5: The last iteration of the article is basically a post-containment document inserted, into the narrative, explaining the previous iterations trapping methodology. Infuriated by this, World-Ender trashes what’s in the room, before calming down after a while. He then proceeds to talk directlyu to the Foundation via the document.
5) Resolution He says that he can wait. Because eventually someone will write about him. Then he can escape, because due to his abilities he can enter any narrative featuring him. He claims that impatience was what caused his downfall, and regrets making his actions in rage a haste near the end, stating that he allowed himself to get distracted form his previous, cunning behaviour. And then he smiles, because he knows he doesn't need to escape for doomsday to happen to the SCP foundation. He claims that while he is the bringer of the doomsday stories, the Foundation will always be the victim of them. In that way he wins. Because his is destruction, and destruction always wins. He starts pondering how the Foundations destruction will go, leaving us with one last word. That if he's so destructive, his creator must be worse. And he feels that the creator is above the Foundation too.