Used to live this game, but not anymore. You need to successfully complete the special events in order to get historical hero cards that provide powerful boosts. It used to be that is you worked diligently on the events, you could complete them on time. Not anymore. They are now designed to be impossible to complete without POURING money into the game. AND, if you do spend the money and complete an event, you only get a "chance" at winning a historical hero. You used to be guaranteed one.