Hidden Base is a highly efficient tough status dispenser. We usually pay 2 ER for a single tough status, so 3 ER for three is tremendous. Moreover, the stocks on tough have continued to rise with the prevalence of steady/stalwart villains and scenarios that punish ally blocking. It takes several turns of flipping to access the value of all three tough statuses, and you risk effects that ping you for one or two damage that waste the tough before it can stop a full villain attack, but these problems can be alleviated with Ready for a Fights. Hidden Base is obviously great with Colossus, who can now consistently start with two tough statuses every time he goes to hero form. Some perfect defense strategies might find the tough statuses awkward, but I think Hidden Base is an automatic inclusion in base-ically (haha) every Protection deck.

As a Basic ally, Yellow Jacket can work in so many different archetypes and aspects.

Also, a key ally for any upgrade heavy hero: Black Panther, Iron Man, War Machine. Also great for Repurpose Protection deck builds. Preparation cards are usually upgrades, so Black Widow and Nick Fury Justice decks want him.

I want to get this in to a Cyclops deck. It can only be played by Avengers. So either another player makes him an Honorary Avenger or Call for Backup gets around the restriction. Then Rapid Response recursion to keep him popping back in to grab Tactic upgrades.

Question, after you see the 3 encounter cards and pick one to tuck, what do you do with the other two cards? Those go back to the encounter deck or to the discard pile?

That aside is also a good card to deal with inconvenient cards, like a nasty treachery regardless of the amount of boost icons.

Ah the Armored Vest + Endurance in one card. And also only cost 3ER (1 less the this two combined) What to say. Amazing, excellent, this card can make a hero a unstopabble force. Someone can say that's a power creep. I preffered... more possibilites. There is few situations when you want to play 1 coster (Armored Vest or Endurance) usually when the hero is 1DEF and you don't want to defend in any way. But even then this provide extra hit points which is useful anyway.

Rating (A-C) A Not a maximum A+, because not every hero wants to defend, but for the value this is crazy good.

A much needed support to help the "attach upgrade to minion" archetype for aggression. A definite auto-include for any Cyclops aggression deck to grab that Priority Target and make Ruby Quartz Visor even more efficient.