It's a neat idea, but I wouldn't play with this card in TFW for the same reason I never played with "reveal opponent's hand" cards in MTG. Unless maybe it was a creature ability. Maybe call it "Double Agent".
But I wouldn't play with it for the reason you think... I'd put it in my deck in the hopes that my opponent would waste too much flux looking at MY hand. I wouldn't bother looking at theirs unless I was in total control of the board.
Simply put, you lose a lot of tempo for information you can't really do anything about. It's more efficient to make your opponent just discard their cards. People bluff in MTG all the time... but I've never been one to "not" attempt the best move I can make because I'm afraid of what is, or what 'might be' in my opponents hand. If you use this ability and find out your opponent has a card like Avalanche in their hand, I suppose then you'll learn that you shouldn't stand next to mountains right? Well if they're playing MF domain, you should already EXPECT them to have avalanche and/or volcano in their hand... so you should be prepared for the worst. There are only so many cards in this game right now, so depending on how your opponent plays, you can reasonably deduce with some confidence what kinds of cards "could be" in their hand. When there are a few sets out, THEN this ability might have some value.
That said, I didn't realize Jett had added so many new people to the list lol.
