I think any deck running black will likely have to consider this for the board, even if they are not running walkers of there own. Just the potential to X for 1 your opponent makes this seem strong, and the time where you are able to put 4 loyalty counters on a Jace or Teferi after killing your opponents 2 walkers seems like a blowout.
@protoaddict No, it's not your opponent's walkers, it is ANY walkers. You could actually drop some of the 3 mana uncommon PWs, drop something with a substantial ultimate, and Elderspell your lesser walkers for a massive pump on your better walker to ultimate in the same turn (or the turn after if you don't have BB + 4ish mana).
If my opponent has 2 planeswalkers on the battlefield... I am losing. And I am probably not resolving this card. Dack and Jace will make it pretty hard to resolve. One of the reasons Abrupt Decay is still good. On the surface this looks awesome but probably won’t see play.
@ssasala Except the 2 PWs could be a WAR uncommon, teferi time raveler + dack or jace maybe. If you are running double black, you are likely clearing the path with seize/duress. If your opponent taps out to play that second walker and doesn't have the FoW, you can get a nice 2-for-1.
I think it'll see fringe SB play and will probably be bigger in Modern, but it can get value in the right situations.
If you have a single walker on the field against your opponents 2 you may literally turn the game around from a loss to a win with this single card. Being able to remove 2 walkers and put 4 counters on say, liliana of the veil just seems to be game over to me.
I think Hero's downfall is more likely to be better in most situations, and that card isn't very playable in vintage (love it in modern). Hitting a pyromancer or monk or vengevine or human is useful. Instant speed is also big. The chance this card will be useful to net any loyalty or card advantage without you already being buried beyond help is small. I suppose in the right matchups (xerox), if you are on a PW build that accesses double black easily, you could get a nice boost often enough. So many vintage decks run 0 walkers though, so this will be bad maindeck for sure.