Well, that MLP community (I ended up mostly on DeviantArt) is ... um ...
interesting, in a variety of ways. Fortunately I discovered there's a whole
steampunk subgenre of MLP art, and that helped narrow things down neatly for my search. Because if we have a Jason pony ...

It's pony
Alycia Chin -- "Payback is MAGIC!" (
source)
Runners-up, who all had aspects I really liked:
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