Soultrader, Rare 40/40/40
Switch Tower, Wall, Ressources, Facilities and cards in hand with opponent
This strikes me as obnoxious and game-halting. Once someone has this in hand, it will either languish due to the cost or that player having the advantage, be discarded to avoid its theft, or cause both players to want to do ABSOLUTELY NOTHING. Other swapping or balancing cards (often maligned in their own right) at least allow you to try to accumulate a decent hand while waiting for someone to make a bold move. This doesn't allow you to do anything apart from maybe playing Inspiration. Several rounds of discarding non-Commons does not strike me as fun.