Finally! The 11th and final spoiled Dark Ascension card from an anonymous source:
Good, but not excellent. It's the type of creature that's designed specifically for any Red Deck Wins deck. It's a 1/1 creature for one mana that can act as spot removal. But I say "good, but not excellent" for one very important reason: It's "enters the battlefield" ability is not a "may" ability!
This means that if you cast a Forge Devil when no other creature on the battlefield, it'll immediately destroy itself with its own ability. This is especially troublesome because it's a 1/1 creature for one mana that wants to be cast on the first turn. And if you go first, it suddenly becomes much less impressive.
(a.k.a. Good, but not excellent.)
Like I said above, this creature wants to be in any mono red deck that has a perfect aggro ramp. These decks want to kill their opponent as fast as humanly possible and because of this, the 1 damage to yourself is completely shrugged off. The 1 damage is insignificant.