MArcomage

"Exchanges all the enemies "New" cards against the last one he played in his last turn". What if the number of cards in each group doesn't match?

I think the meaning is that all the new cards would be replaced by the very last card played by the opponent

I wonder what happens if the opponent's last action was to discard something. Would he receive the discarded card, receive the Quick/Swift card played last (if applicable), or would nothing happen?

FilipeSilva:
I think the meaning is that all the new cards would be replaced by the very last card played by the opponent.

That's right.

If the last played card was discarded the opponent would receive the discarded card again.
The last card played can't be quick or swift, since you always have to play another card after the quick/swift card (or discard one).

I think Forced Infinity opens lots of ways for interesting strategies. Maybe it's even more usefull to have the card effect working on yourself instead of the enemie. There could be other cards that f.e. give stock+3 and discard all cards with "keyword". If you play forced Infinity in your next turn, you would receive x (number of discarded "keyword" cards) cards with the stock+3 effect since you now have x "New" cards.

I didn't say the last card played was Quick/Swift. I was asking about the last card being discarded AFTER playing Quick/Swift.

In any case, you've answered my question, but I think the card text needs to clarify this. Currently it say the last card "played" which suggests that it would ignore a discarded card. "played or discarded" would straighten it out.