Sidekick is really interesting for Drax, who needs to keep Mantis around for as long as possible. With Side-by-Side you can also use Mantis to thwart sometimes as well. The trouble with Drax is that he will be aiming not to use a basic recovery at all, so the response on Sidekick goes to waste with him. She-Hulk is a hero with a key identity-specific ally who tends to make a lot of basic recoveries, so I think she is an excellent match for Sidekick/Side-by-Side. Phoenix is another hero with lots of reasons to go into Alter Ego and who benefits from a basic recovery. If Cyclops never comes off the board then his response essentially means that Sidekick was free, and the Sidekick/Psychic Kicker combo seems pretty appealing.

I'm surprised that there don't seem to be many decks using Sidekick with those heroes yet.

More of an oddball choice but I'm interested in Sidekick for Ms Marvel. She wouldn't benefit much from Side-by-Side but 2ER to make Red Dagger immortal seems like a good trade to me and worth exploring leadership for her.

I thought this card might be useful until I noticed Clarity of Purpose. Why is this so much worse than that card? Potentially, Adam Warlock might like this since he can use it before using Soul World to restore himself to full hit points, but using it without a counter on Soul World is skirting disaster. Plus, Adam Warlock can always use Clarity of Purpose.

I made a Thor deck recently (link here) and played it several times, and Shadow of the Past came out in the first few rounds of over half of these games, so I've had to deal with Loki many times. From this, I've learned a few things about dealing with him that I'd like to share with you:

• Don't forget that when Loki comes out, you still get to draw 2 cards from your "Have at thee!" ability because you are still engaging a minion.
• Prioritize dealing with Family Feud over dealing with Loki, because Thor is better at defeating minions than he is at thwarting. Defender of the Nine Realms works against Family Feud just as well as it does against any other scheme.
• Hitting Loki with Overkill attacks makes sure your damage doesn't go to waste even if he does heal himself back to full. One time I had a lot of fun putting a Marked* on him and just clobbering him over and over.
• Vivian* shuts off Loki entirely! I've been slotting her in all my Thor decks for this specific reason.

*I know Marked and Vivian came out many cycles after Thor, but still.

Moon Girl and Pinpoint are a great pairing in my opinion. Worth considering for any -heavy Champion deck, and especially for Ironheart. The more times you shuffle Moon Girl into your deck, the more card draw you have, and drawing cards never hurts in this game.

Honestly, a great thematic match to Madam Masque throughout the last 2000's. Tied SO tight to The Hood. In The Hood, the scenario, she can be a rough one-two punch if Foul Play activations start mounting. An easy to overlook card, that provides the makings for a good story.