MArcomage

Faceless Void, Rare, 18g10r
Quick
Attack: 34
Neighbors of this card and selected
card and its neighbors cannot be played for 3 turns


There have been other similar suggestions in the past, but unfortunately continuous effects are not supported by the game's engine. There's no way to prevent a card from being played if the player has the resources to do so. The best similar thing you could do is to have it replace those cards with another.

Something else that had been suggested once was to replace a card / all cards with another card that has the effect to redraw a/all just-discarded card(s), causing the opponent to "lose a turn" in a sense, but it seemed like it would just prove to be an annoyance while applying the New flag to everything (and hiding them in Hidden mode).

Sounds too much work for only one turn effect

Faceless Void, Rare 18g10r
Quick
Attack: 28
Opponents Hand,Facility and Stock are set to the same as it was 3 turns ago


Also not possible. Only changes that are still discernible onscreen can be undone, or a reset to initial values. There was speculation that things like this could be done once the history module was implemented, but when it comes down to it, any card where the effect can't be determined simply by looking at all of the visible numbers and cards (Hidden mode notwithstanding) can be a headache. You shouldn't have to go digging through History to calculate what will happen when a card is played.

Furthermore, someone drawing and immediately playing this, undoing things that happened before it was dealt into the player's hand, is rather obnoxious in a game that's focused so much on strategy and planning.