This has the potential to be very efficient threat removal over the course of a long game, but there is a point where efficiency fails due to slow speed. It's really important to have your threat removal deal with side schemes, and this can't do that alone in a timely manner. War Room also fails to tip the balance from a you-killing-minions strategy to an allies-killing-minions strategy. Cards like Chase Them Down and Hall of Heroes are staples for aggression, and they won't be activated when an ally kills a minion. There are many other great cards like Magik, overkill cards, and if this attack defeats cards that provide extra value or are really good at killing minions that would have to get sidelined by a War Room strategy. War Room is niche playable at best, and certainly give yourself other options for threat removal in the game if you include the card.
Location.
Max 1 per player.
Response: After an ally attacks and defeats a minion, exhaust War Room → remove 1 threat from a scheme.
This is basically the Aggression version of Interrogation Room which I sometimes add as a one of. Its not gong to fit in every deck but in aggression it can be a nice smoother for the right deck.
The big downside with many cards of this ilk is that unless you are playing big multiplayer sets minions arent really reliable or practical to build around. That being said, as opposed to playing this card as a a primary strategy card it can fill a situational role-card slot that is played when the situation/hand fits.
So far I find this card to be a lot more interesting inside an X-23 deck. This is mostly due to the ping efficiency you get with Honey Badger and how consistently she can get on the table. You dont need to play the card but at the cost of one its a nice resource dump for later use.