A sample Standard Leadership Deck

This is a fairly vanilla Standard Leadership deck.

The allies are fairly standard fare.

Lead from the Front for burst damage

Get Ready is a combo card that is strong with Vision but also good with Maria Hill (comboed with Make the Call) and is also good with Nick Fury.

The Flex cards are mainly Get Ready and Triskelion, and to a lesser degree, Lead from the Front. Other options include Teamwork , Inspired, and Rapid Response. Mockingbird and Heimdall are alternate ally possibilities.

Changes you might make with other heroes:

Captain America - Morale Boost can be decent due to his hero ability. Since Agent 13 is essentially the same as Falcon except cheaper, Falcon is optional.

Captain Marvel - You probably want to add Enhanced Reflexes and you want to prioritize energy cards such as Teamwork, and Lead from the Front.

Spider-Man - Due to Web Shooters, Quincarrier is less necessary and can leave it for a Teammate. Also, you will want to add Inspired to this deck to combo with Black Cat. And since you have Inspired, you can add Iron Man ally.