I wanted to go theme-y with him so I added Goliath to make it all the size-changing allies, plus Iron Man and Ronin to get the best effect from the ally upgrades. Having 7 upgrades that have to attach to allies can give me janky hands where I draw all the stuff to boost allies but no actual allies to play them on. Cutting Call for Aid entirely kind of hurts in that regard but I'm fine with it since the real solution should be to cut 1-2 of those upgrades. Running 3 copies of Team-Building Exercise is too many and that was a problem I also had with just the preconstructed deck, currently going with a single copy but 2 in Scott also seems fine. I also got rid of Moxie even though it's best in Ant-Man (and soon to be Wasp) decks. Inspiring Presence to get more swings out of loaded-up guys like Giant-Man and Goliath fits better with what I want this deck to do. Anyone with an Inspired and Power Glove makes a great target for readying too! https://marvelcdb.com/decklist/view/5187/lang-s-big-tall-1.0 Only played solo so far and haven't done more than a few bouts with Rhino and a single battle with Klaw but it's been fun.

Avengers Tower and Team-Building Exercise can indeed be used to reduce an Avenger ally by 2. You'll have to use the Tower first since it's a floating effect and TBE is a combination of immediate reduction and playing of the ally. I knew Scott was going to be fun and good so I started out with the preconstructed deck against Expert Rhino and Legions of Hydra. LoH on the first turn in two of three games was awful and the 3-boost on it made me lose to an untimely Advance. I tuned the deck up to try Expert Rhino with Masters of Evil and simply crushed him. Expert Klaw with MoE took a bit long and was more fun. Can't wait to play him with friends and also with the Wasp!

Champions wasn't built for head-to-head play so it would be interesting to see how they make it work. Love the Annihilation suggestion - not only was it a great story with a fun cast, it would fit in nicely after/during the Guardians campaign and cycle. Annihilus is one of my favorite villains in the comics so I'm up for a battle with him.

I'm fine with Wanda having two obligations and I wouldn't be surprised to see another hero get that in the future. There's plenty of design space to explore with Obligations, what they do, how they're removed, and so on. Future Obligations could summon or enhance a Nemesis, cause problems for other heroes, buff villains, or more - I'm excited to see what they can do. There are times now where an Obligation comes up and it's just too tactically risky to exhaust for removal. Having meaningful options when choices come up is good design. Her extra one could be very nasty at times and I think it's a good balance to a powerful character who can also manipulate the encounter deck.

Get some Earth's Mightiest Heroes in that Ant-Man deck! Protection Giant sounds neat too.

What Aspects or combos are you playing or want to test with him? I'm going to try Leadership with the new cards and Goliath to have the size-changing allies all together but other than that I don't feel he really has any particular synergy there. His Justice card is neat so I may try that next, then switch him to Aggression when Janet Wasp comes out in Nadia Wasp's pack.

She looks like a lot of fun. A better execution of 'extra power with drawbacks' than the Hulk.

Very true, though Leadership has plenty of other good Allies to fill the gaps until Felicia shows up. In particular, Goliath and Iron Man are tailor-made for doing the same sort of thing. I agree with OP that Team Training and Reinforced Suit aren't me as necessary for her in particular since she's more suited to attacking, though they'll help when facing Concussive Blast, Thunderball, and indirect damage, or provide you with more cushion to thwart with her if needed. As for a Black Cat hero, I'd love to see her with a hero power or a number of hero cards that involve milling a card from your deck or the encounter deck for extra effect, a la Hulk Ally and/or that one Scarlet Witch card that counts boost icons. I loved her first card in Vs. System since it did similar things.