As an action while flying, you can use the Dash action. If you move at least 6 meters in a straight line angled downwards toward a creature, you can make an Attack action with a melee weapon attack against it. Add the stamina die to the attack’s damage (add half if you miss by 4 or less). On a hit, you don’t provoke opportunity attacks when you fly out of the creature’s reach.
You can increase the damage for each additional stamina die expended.