Mulligans
General Mulligans
Obviously if you get a good curve or combo (ex. turn 1 quest turn 2 secret turn 3 coin alpha, or Missile Launcher Venomizer), you should keep those cards. Otherwise high rolling for the duplicate in your deck (swarm of locusts) to make your zephyrs and Brann work is key.
Where did all my dust go?
Only make this if you already have some of the legionaries