For 4-ER, you can consistently neutralize an attack from a weak minion every turn for the rest of the game.

Danny really wants to be a Voltron ally though, with you stacking Inspired, Sidearm and similar cards on him to amp up his power so he can start tanking hits from the villain. If you use both of those with the new Righteous Purpose, you can get him to 6 ATK and fairly consistent block the villain.

That's a high investment to get him built up there, but I suppose it's worth it to prevent all that damage.

He's very similar to Echo but I think she's usually better since she doesn't need to be down to 1HP to reach her full potential, and Protection has access to Hangar Bay to let her block multiple times. Although one advantage he has over her is that he can block for teammates in multiplayer if you need to go alter-ego, while Echo loses her protection if you switch down.

This is a card that you won't want to throw in just any deck, but it could make you really durable in the right type of deck.

If you're doing anything with this, there are four cards I would suggest using.

You should first use Ready for a Fight and Practiced Plan to be able to consistently switch back to alter-ego as needed without letting the villain scheme. 3 copies of Ready for a Fight with 2-3 copies of Practiced Plan would be best.

Second, you should use a copy of both Endurance and Defensive Conditioning to get +6 HP, making it easy to heal above your base hitpoints without losing value.

In the right deck, this is going to be fantastic and help you trivialize damage even more than Protection already does, letting you reliably get a tough card every turn so long as your HP stays in the right range. Which, with multiple cards increasing that HP, should be a pretty wide range to be able to hit consistently.

Without Maria Hill, it's hard for this card to be worth it. Captain America and Hercules are fine and all, but they're not really developed assuming you're going to pay 6 for them. Heimdall is probably a more realistic cost for the best ally you'll play with this.

So, you've played 7 effective resources for the Circe, and each hero is another effective resource, bringing the total to 9. Playing Heimdal and Giant Man from your hand would cost 12. You've likely spent an entire turn just playing Circe, and then you have to wait to draw your giant allies, and can play one a turn. Also, if you need to be putting out fires, you can't afford to spend 6 on this, and you are drawing these giant allies who are of limited use in most decks.

I'm not saying it's useless, but it definitely shouldn't just be thrown willy-nilly into decks. You need to consider the costs/risks.

Why does this card have Alliance? WHY?

Seriously, WHY? Alliance is a keyword that allows players to split the resource cost of a card. Sounds great, right? Except THIS CARD COSTS ZERO.

What exactly are we supposed to split here? There is literally no cost to share! I can understand Alliance on expensive cards, where sharing the cost actually makes sense. But putting it on a 0-cost card is like giving someone a discount coupon for something that's already free. I don't know who made this decision, but I desperately need an explanation.

WHY DOES THIS CARD HAVE ALLIANCE?!

Might try a Symbiote Suit build with this, granted in SOLO the extra hand draw from it can be allocated for the resource requirement each round. But in multi-player it may be too demanding for other people to pay a resource just for your singular benefit