Due to this, I think there should be either:
A) a warning at the top of the screen whenever there is an Urmian Psychic Cage still in play
B) a way to back out once you try to play a card and are made aware of the cage. Like: instead of just "would you like to (sacrifice this card) or (sacrifice a card from your hand)" another option could be added to (cancel playing this card) especially since the player hasn't actually played the card yet.
I think option A would be easier to implement, but I would be happy with either solution.
I know a lot of people will say things like: "You should just pay more attention to the table" and I feel like maybe those people don't play Turn-based as much as I do. When you only log in for your own turns, you could easily, and understandably miss that the Cage has been played. Especially if it was played by a player whose tablaeu is off the bottom of the screen.
ALSO: the graphic that is supposed to show if the Cage is still in effect is totes borked, which could also cause misunderstanding.
I posted the suggestion in the bugs/suggestions board. Please vote for it: https://boardgamearena.com/#!bug?id=12487