Collision of worlds, Rare 65g
Destruction
All players suffer:
Facilities: -3
Tower := 1
Wall: -100
Stock := 0
This card is far too inexpensive for something that the player can (and will) only play when the opponent either has no 0-cost attack cards or the player has sufficient wall to survive and ensure a win on the following turn.
Something to bear in mind is that this turn will end with the opponent having 0/0/0 and the player of this card having 1/1/1 (or more if any facilities were 5+) due to production. I won't go through and count the Common cards that have Attack or Tower- with a cost of 1/1/1 or less, but it won't be an unlikely scenario.
All that aside, what's worse is the possibility of playing this card when it doesn't ensure a win right afterward, potentially as a stalling tactic. Typically, when a card "resets" some aspect of the game, it chooses one or two features. Having your wall and tower arbitrarily set or averaged can be annoying, but your stock and facilities are generally left intact. Alternately, having your resources drained and your facilities reduced can be a hindrance, but all your progress building or attacking is untouched. This concept is likely to erase the gains and losses of the entire match AND leave players with facilities set to 1, two entirely obnoxious scenarios that bleed the fun out of a match.
My proposals are to either retool this as an actual guaranteed insta-kill with a heftier cost or to scale back the effects either by making it conditional or having the player choose what elements to affect. Another option would be to have the reduction to facilities only affect the player of this card, still leaving the opponent with 0 stock but giving them the chance to recuperate if the death blow isn't dealt immediately but leaving the player of the card in dire straits outside of certain deck strategies (0-cost, self-cripple). And even then, I'm not sure I like that it hits three things: wall reduction as well as arbitrarily setting stock and tower.