The objective of this deck is to play all your ongoing cards to a location that you can end up buffing them at with either Onslaught or Spectrum.
Optimal Turns (Priority Order):
Turn 1: Squirrel Girl (Unless you have Onslaught and Ant-Man in your hand, then play Ant-Man now / Skip Turn)
Turn 2: Ant Man / Skip Turn / Any of the other 1 cost cards recommended
Turn 3: Captain America / Mister Fantastic / Cosmo
Turn 4: Ka-Zar
Turn 5: Blue Marvel / Devil Dinosaur / Iron Man / Klaw
Turn 6: Onslaught / Spectrum
Optimal Lane Combos:
Combo 1 (Any Lane): Iron Man, Onslaught, Captain America, Ant Man
Combo 2 (Middle): Mister Fantastic, Captain America, Iron Man, Onslaught
Combo 3 (Any Lane): Captain America, Ka-Zar, Blue Marvel, Onslaught
What do I do if I don't pull Onslaught or Spectrum?
This can be a bit tricky since this deck heavily relies on the power burst from both of them. If you don't end up pulling either of them, drop Devil Dinosaur onto any lane you think can win you the game if you have him. I like to play him on the same lane that I dropped Klaw on as my Turn 6 reveal.
Use Cosmo to shut down a lane before your opponent can play Enchantress / to mess with their on reveals. Since only one card in this deck is an on-reveal, you should have no problems playing around him. Definitely drop Cosmo onto the lane where you will be playing Blue Marvel and Onslaught to prevent yourself from getting screwed turn 6 if you feel uncertain. Cosmo is the only real conditional card in this deck and can be replaced with any 1-cost supporter card if you are not using him too much.
The sheer power of Onslaught is enough to generally win you any location, especially if played to the same location with Blue Marvel for 12 power total (7 + 2 from Onslaught, 3 from Blue Marvel). If you don't pull Blue Marvel, Iron Man is also another great substitute for putting in the same lane as Onslaught for a total of 28 power (7 * 2 * 2).
If you don't pull Onslaught by turn 4 and have Spectrum in your hand, consider spreading your cards out a bit and prioritise cards that give power to multiple cards / locations such as Mister Fantastic, Captain America, Ka-Zar, Klaw, and Blue Marvel.
Squirrel Girl is your main way of spreading out as this deck only really lets you play 6 cards in an average game. She will definitely help win you some lanes that you normally would not be able to reach and you should prioritise playing her whenever you can.