Merchant's Porter - 1
Artifact Creature - Construct
3U, T, Tap X untapped artifacts you control: Look at the top X cards of your library. Put one of them in your hand and put the rest on the bottom of your library in any order.
We know all the masterpieces already. But since Ornithopter is a masterpiece and also in the set, it's possible that other masterpieces are in the actual set.
Though, looking over the list, there's not very many candidates. Lots of them are the sorts of cards that they wouldn't print into standard, have keywords for other sets or wouldn't want printed into modern.
Pithing Needle seems like a strong candidate though.
Given that, the use of "target player" is a bit odd. Perhaps its a way to use the spell on your own creature (for revolt) and still damage your opponent. EDIT: Oh, and if your opponent has no creatures.
Also, interesting how Rishkar mentions "counters" instead of +1/+1 counters like the outlast creatures in Khans of Tarkir. Perhaps Amonkhet will use -1/-1 counters.
I agree that that's likely the character's motivation. But being the villain often isn't defined by the way the person sees themselves. Many of history's greatest monsters feel they are in fact on the side of good.