a little question

It's just that the Agents have to wait until they get to a significant breach of Canon. Some agents find the first major breach; others wait for one that's better for their purposes. For example, Agents Nume and Ilraen and Nurse Robinson waited until their Sue in "Blood Raining Night" tried to give birth to God to charge her, despite the entire fic being a trainwreck of a Canon breach. In contrast, my Agents usually wait for the first major breach of Canon to charge the Sue because usually by then the fic is just too annoying for their mental health to continue (or, in case of a recent mission, triggered one of the Agents so they kinda have to get out there as soon as possible).

If there's an OC without enough charges to justify a killing, usually they're recruited into the PPC or dropped off into another continua with their mind wiped. Frequently, bit characters that are generic enough assimilate back into Canon.

"Blood Raining Night" is a megacrossover, and it's not set in any of the canons it mentions as far as I can tell. I treated it as an independent reality sustained only by the will of its Mary Sue, which is why the whole thing collapsed at the end. A canon breach as such isn't really possible under those circumstances. The best you can get is a violation of the story's own internal logic, but BRN set the logic bar so low it took a lot to reach the equivalent of a canon breach. Basing your existence on an unstable paradox whilst blatantly failing to understand how pregnancy works and claiming you're so awesome that you're the mother of God fit the bill.

Also, the Sue was nicely incapacitated and her only friend around was out cold, so it was the best place to strike strategically. Nume and Ilraen generally try to isolate their target as much as possible, since it makes the job less dangerous—this is one reason they waited as long as they did in "Ring Child," too. Even with Suicide and Diocletian as backup, they couldn't have taken Archir the Emerald down while he was protected by the entire Fellowship of the Ring.

And finally, the main reason my agents strike when they do is that I choose the point I think will make the best story. The point where the agents do the Duty is the climax of the story, so it should be the biggest thing that's happened so far, and it should tie together whatever themes or arcs are present. Reicheru giving birth to God is far and away the most ridiculous, over-the-top, arrogant thing I've ever seen in any fanfic, so it had to be the kill point, even though I could have reasonably chosen an earlier point, such as Kagome's torture or the "aborition." Both of those things were made so much worse by how the story neglected them afterward, though; stopping at either of them wouldn't have done them justice.

I basically agree with what you said, though. There has to come a point where you can make the case that the canon/internal logic is officially ruined, and the charges you've gathered up to that point must be enough to support the case, whatever they number.

~Neshomeh