Technically this card could be read as :
Before the start f the game, you must spend 2 ER then replace this card with an Identity Specific ally and shuffle it to your deck.
Some IS Ally are worthless with this because they work specificly with their hero, using their gimmick.
But you can have in every deck Black Cat, Captain Marvel, Mantis … You could go Sidekick with them …
The possibilities are impressive … for a cost. You are forced to discard two cards which slow down your first turn a lot. I really want to test that card to se if the cost is Worth the reward.
But yeah, I really want to try this card, to see what broken combo can be made by adding an ally to a hero that shouldn't have it.