Looking Glass
$4 - Treasure - Command
Play a non-Command Treasure from the Supply, leaving it there.
Each other player may gain a copy of it.
In basic Kingdoms, Looking Glass offers you the flexibility of playing it as a Copper, Silver, or Gold, with the caveat that your opponents may choose to gain a copy of the emulated card. I think it will probably get played most often as a Silver, with players only needing to play it as a Gold to hit certain price points.
Looking Glass will be more interesting when there are Kingdom Treasures available e.g. Scepters and even Loan. There is a strong combo with Capital, but if opponents choose to gain Capitals, the pile will eventually empty and so players will no longer be able to exploit the interaction between Looking Glass and Capital. However, if it turns out to be broken, I suppose the card could be revised to have similar wording to the original Overlord in order to avoid that.
There is no cost restriction, so Looking Glass can be played as Platinum or Fortune; players would just need to assess whether they will benefit more than their opponents.
There is a danger of piles running low quickly in games with more than one Kingdom Treasure (or Capitalism games), but those situations should be rare.