Wagic, the Homebrew !?

I already checked, there was one reported bug regarding this card, but this is a different animal.

Slaugther pact will win me the game if my opponent doesn't pay (2)(B) during his upkeep, the effect of the card is that I can slay any nonblack creature and I will lose if I don't pay during the (2)(B) my upkeep (Zero mana cost).

So there is that.

Aaaaaaaaaaaaaand unsurprisingly, it also works the other way around, the AI has just won the cheapest of games at turn two.