"What is the stupidest deck you can build with Forge and still have it work somewhat?"
I don't promise to be good, but I do promise entertainment. And Science.
Combo lines:
Forge has 3 primary targets in this deck: Brood, Iron Man and BP. The deck is pretty much a Wong deck and you can pull off some non-Negative combos. Some examples:
Wong (4) -> Mystique + Forge (5) -> Brood + Wolfsbane (6) - Doesn't need Negative. When you pull this off, your Broods gain +8 Power before reveal, becoming a 3 for 30. If you are using Bast and gave them a Bast Boost before hand, they become a 3 for 33. Wolfbane will get 4 activations and +6 each so +24 for 25-27 Power depending if she was inverted.
Wong (4) -> Mystique + Psylocke (5) -> Black Panther + Taskmaster (6) - Again, doesn't need Negative. Pulling this off gives you 10 Energy to spend on Turn 6. BP will then multiply himself 4 times and hit 64 Power. Tasky then copies BP for 64 Power in another lane.
Zabu / Psylocke (2) -> Wong (3) -> Forge (4) -> BP (5) -> Zola (6) - No Negative needed. A very long string of plays that culminates in Panther starting at 5-16. Play on an empty lane, then copy him with Zola.
Where the REAL fun starts if Negative hits the deck. Then depending on what you draw, you can get some real silliness going:
Zabu (2) -> Negative (3) -> Inverted Wong + Mystique (4) -> Forge + Brood (5) -> Inverted Wolfbane + Taskmaster (6) - You can swap around some of the inverted cards, but the combo is the same. This results in hitting all 3 lanes with massive 20-30 powered cards. With Negative on 3, you also have a chance here to draw Inverted Iron Man to generate massive power in any one lane.
Zabu (2) -> Negative (3) -> Inverted Wong + Mystique (4) -> Forge (5) -> Inverted Iron Man + Zola (6) - Creates a 0-13 Iron Man that doubles score (so for 0-26), which you then Zola to the two other lanes.
Zabu (2) -> Negative (3) -> Wong (4) -> Mystique + Forge (5) -> Brood + Wolfsbane + Inverted Taskmaster (6) - Same deal as (1) but different order of play and only requires one Inverted card.
Zabu (2) -> Negative (3) -> Wong (4) -> Black Panther (5) -> Zola + Inverted IM + Inverted Mystique (6) - Some RNG involved, but the end result is duping Wong + BP again into 2 other lanes. If Wong goes before BP (50/50), BP gets an extra activation. Inverted IM and Mystique then do their thing.
THINGS TO WATCH OUT FOR:
For once, Shang is a nuisance in this deck because you will get your power above 9 as a goal. However super regular Iron Man floats just under the 9 power, giving you a reason to actually play him if you set up the Wong combo.
The standard Wong disrupters are all going to spoil you. So you want to try and set up your combo in one turn - which will really depend on which cards are inverted. The earlier Negative comes down, the greater the chance of you being do a large dump on Turn 5/6.
Careful of Surfer decks in particular. Not only CAN they run Cosmo to spoil you with priority, but Shadow King will reset your buffs if they don't have priority. This is a match where fighting to lose priority is key. It shouldn't be tough because your board will be mostly low powered cards, but hand dumping too early can result in getting Rogue'd or Shadow King'd.