I quite enjoyed this story. There were some very good character moments. The introduction with Su getting into Internet arguments over (what I assume is) Greek culture was particularly entertaining. The two new characters did feel a bit flat, but I attributed that to this being their first appearance/mission.

I will admit to having a few complaints. While the breaking out into song was a great touch, I wasn't too fond of some of the other fourth-wall-nudging bits: Su's use of italics and the reference to the wiki, to be precise (unless there is some sort of in-universe PPC Wiki, which I could see happening. I could also see such a thing being almost constantly locked from outside edits). I also didn't much care for the little excursion into Gen 1. It felt a bit too randomly wacky, especially since it played no impact on the plot whatsoever.

All in all, very nice work. Definite kudos from me.

Two typos:

I hope that’s not what is sounds like, because I’m getting sex-pollen flashbacks.

Maybe some of of us should check here while one checks the schoolroom!

HG

...if a mission calls for a mad bomber, let me know and I could loan you Cloud Mushroom for the mission.

Though I would have thought that the mission would be a bit more … substantial given how notorious it seems to be within the brony fandom (and given that the legendary Tawaki himself came out of hiding to spork it!), I must say that this is nonetheless a good mission. And a fitting end for Not!Cheerilee.

Allow me to add to the chorus saying that the "This Day" rendition was a good touch, however, if Herr Wozzeck were here, he might point out that the lines don't exactly scan.

As for errors, I haven't caught any—at least, not in the English. There is, however, an error in the Greek. Granted, my experience is in Ancient Greek, not modern, but even still, that was enough to tell me that something was amiss. Apparently Google Translate is just as bad at modern Greek as it is in Latin.

Either way, given Suicide's background, he should be speaking in ancient Greek, not mangled modern Greek. "Love" is easy to translate, but as I cannot find a word for "tolerate"; I chose a word for "be patient" instead:

"Love and be patient"-->"αγάπα καὶ καρτέρει"-->"agápa kaì kartérei"

That aside, good mission!

P.S.: After poking around a bit on Wikipedia, I might have figured out exactly what went wrong on Google Translate's end of things.
What you wanted were a couple of imperatives. If my (admittedly sloppy) research is not mistaken, what came out were two third-person plural verbs, one in the present active indicative, and one in the present mediopassive indicative: "they love and they tolerate/they are tolerated/they tolerate each other"

I thought the italics lampshading would be my favorite part, until I read the song that the agents broke out into near the climax. I'd definitely recommend that sort of thing for agents visiting musical continua like this one!

Oh, and, uh...

“My name is Éowine son of Isenwine.” I think there should have a comma after "Eowine". Ditto for “And I am his wife, Steormægð daughter of Æþelmearh. (comma after Steormægð)

Suicide being a brony is what made this for me, though. After all, Real Men Wear Pink!

It felt like it was cut a bit short, but other than that, well done, everypony. *offers zap apple jam as condolence* :)

It's set to 'everybody with the link can edit' right now.