Cap's Trio Featuring Iron Man

The goal of this deck is to load up Iron Man with all the upgrades and let him go to work. Mid-late game, with Mighty Avengers and Team Training in play, Iron Man will have 4 thw, 5 atk, 6 health, ranged, and at least one ready each turn - plus he'll do 1 damage with each attack or thwart thanks to Power Gloves. Best of all, each of his upgrades are free!

Heal Iron Man for 1 and ready him again using Inspiring Presence. Get another heal from Innovation. And if he does die, then bring him back right away with Rapid Response or grab him AND a free upgrade with Suit Up.

Clearing Build Support helps get Mighty Avengers or Quincarrier out. Bonus points if Mission Leader is in play before you clear it - it only costs 1 resource due to Cap's Soldier trait (which he has in Alter Ego, too!).

Honorary Avenger has two copies - one for Cap and one for Agent 13 to make sure the +1thw / +1atk benefit from Mighty Avengers stays active the whole game, even while in Alter Ego.

Crew Quarters and Steve's Apartment help keep up with Cap's injuries.

Suggested Variations
For scenarios without many side schemes, I would replace Mission Leader with 1 copy of First Aid for some bonus Iron Man heals.

If you find yourself wanting to keep Agent 13 in play longer due to high sustained threat, then Sidekick will provide her with healing every time Cap recovers. You could even add a 2nd copy of Inspired to grant her an extra thwart.

For scenarios where Cap won't take a lot of damage, you probably don't need both Crew Quarters and Steve's Apartment. Drop Crew Quarters for First Aid, Sidekick, or even another low-cost Avenger's ally like Squirrel Girl to help clear the board of tough statuses or Stinger for cheap blocking.