The game is also running a "buy a hero, get a hero" promotion that lasts until the end of Monday. Through this, the purchase of any hero (other than Dr. Strange) will give the player a second, random hero (other than Dr. Strange) for free. If the player gets a duplicate of a hero he or she already owns, the bonus will then be a token to upgrade that hero's ultimate power.
You can check out the Dr. Strange trailer after the jump!