NOTE: This card has been buffed in Rules Reference 1.7 and now reads:

Alter-Ego Action: Search your deck and discard pile for an ally and an upgrade that can be attached to an ally. Add them to your hand. (Shuffle.)

"Can be attached to that ally" has been changed to "can be attached to an ally".

This means you can now find any ally plus any upgrade that can be attached to any ally in the game. For instance, you can fetch a non-identity specific ally and Sidekick.

NOTE:

On the Angel decklist card, this card is erroneously listed instead as Triage, a completely different card from AoA)

I find this card very strong. 2 ER for 1 thwart or attack and then a chump block. This is an auto include for most Avenger Leadership decks to me. Very strong with Captain America, Strength In Numbers, Band Together, and Earth's Mightiest Heroes. Stinger can also be played for free with Team-Building Exercise or Avengers Tower. Not counting against the ally limit means Cassie can be played at any time without risk too.

Rating: high A (S-D)

In my opinion, the best aspect card in the game. I don't like to call cards staples, but this fits in nearly any deck. And even if you have a perfectly fine 40 card deck and you play a scenario with a few 2 ATK non-guard Minions with a nasty when defeated effect or something like that coughthanos, tower defense,cough, you can just throw this card in and it will help a lot. Even if it just saves you a basic attack for 2, it's still practically 2 damage for 1 ER, and perfectly on curve. I also love it for Tigra to just collect the minions and keep them shut down. Hunted even ignores guard, so the weak, guard minions that are nearly in every scenario can be targeted. But it's situational and not an energy resource for the protection cards that want one. It can happen, that there is no target or just a 4 ATK minion, that you would still need to kill.

Possibly one of the worst identity-specific allies in the game, together with War Machine and Diamondback. Absurdly expensive, especially for a hero with a hand limit of 4 and a desperate need for resources to pay his powerful identity-specific events. Her Response is... okay, I guess, allowing Thor to make another basic attack, or to recover from Odin's Anger, but nothing I'm swooning over. In over a dozen games with Thor, I haven't been able to use her once.

My final verdict: Lady Sif, I want a divorce.

(either that, or I'm house-ruling her a cost of 3)