system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] What relationship, if any, does the Green Lantern Corps have with Apokalips?

Rather self explanatory, I think. And before everyone starts going off on how Apokalips and the New Gods are more of a concept then anything physical (see Multiversity for a more thorough explanation), let be more specifc and state what relationship they have with the physical 'Avatars' as it were.

Because Apokalips has launched Boomtubes of Parademons at Earth and other worlds who knows **how** many times, and I can't think fo any instance on the Green Lantern Corps actually doing anything about that problem (although my list of comic books I've actually read is depressingly low, so I might just be ignorant of a certain event or whatnot).

So, what's the deal? Do they just ignore that world and its actions? Are Parademons and such just too much for the Corps to handle, or are they somehow ignorant of that worlds existence and its crusades (unlikely, I know)?
gpt
The Guardians held a protracted war against Darkseid, and lost, as Darkseid exploited the yellow weakness of the Rings to his advantage. A sole Green Lantern was stationed on Apokolips undercover, primarily to observe. But the Guardians found that their efforts were best placed elsewhere, and left the war against Darkseid to New Genesis.