Here it's the link of the site. http://www.digitalmonsters.net/DVR/index.html
I'll own up: it's a mistranslation on my part. Though, to be honest, the lack of a profile for Apocalymon (either through Digimon Dictionary or otherwise) is also to blame. Not even his Japanese entry in the Sunburst/Moonlight games clarifies his connections with Millenniumon. Here, then, is the real translation:
A Digimon whose form was conceived from the negative thoughts of man and the grudges of Digimon who fell without being able to evolve. The appearance of Apocalymon was written down in an ancient book of prophecies. The various grudges of regretful Digimon are stored in his big body, which is also jam-packed with information on those Digimon, such as their evolutions and both special and signature attacks. But his real body is the one on top of the big body. It's said that Apocalymon was once sealed away somewhere until his restraints, the same ones created to hold back Millenniumon, were broken.
So, yes, TV Tropes got hold of a translation I mis-translated, so we are both in the wrong.
The Digimon LiveJournal / WiththeWill Profile Translation Project
Currently Working On
1. Digimon Dictionary / Digimon Life Re-Translations
2. Digimon Card Flavor Text Translations
So, Apocalymon is also sealed behind that "Digimon Channel" url-band?
No, that's Zeed. This seems to just be talking about the Wall of Fire.
It seems to be a reference to the barriers separating the Dark Area / Dark World from the rest of the Digital World.
Possibly. Though we're talking about general canon here rather than Adventure canon.