Action: Ready an ally.

Hawkeye
Clint Barton
Avenger.
Hawkeye enters play with 4 arrow counters on him.
Response: After a minion enters play, remove 1 arrow counter from Hawkeye → deal 2 damage to that minion.

Condition.
Attach to an ally. Max 1 per ally.
Attached ally gets +1 THW and +1 ATK.

Tactic.
Hero Action: Choose a player. Each character that player controls gets +1 THW and +1 ATK until the end of the phase.

Action: Pay the printed cost of an ally in any player's discard pile → put that ally into play under your control.

S.H.I.E.L.D.
Response: After Maria Hill enters play, each player draws 1 card.

Max 2 per deck.
Double the number of resources this card generates while paying for a Leadership (blue) card.

Location. S.H.I.E.L.D.
Increase your ally limit by 1. (This allows you to control more than 3 allies.)

Android. Avenger.
Action: Spend a resource → choose THW or ATK. Until the end of the phase, Vision gets +2 to the chosen power. (Limit once per round.)
