In Zenith, the Leader badge allows you to hold more cards in your hand at the end of your turn, giving you more options for acting and reacting to your opponent’s moves!
Without the badge, you must top up your hand to 4 cards at the end of your turn. If you have it, you’ll be allowed to hold 5 or 6 cards, depending on its level. Getting it – and keeping it – is invaluable!