Mulligans
Combo Mulligans
Against heavy control classes, keeping Aviana/Kun is mostly the correct play in the case you draw Embiggen early and it stops it from becoming a dead card. Against aggro you die.
Combo: Draw both Aviana and Kun before you play Embiggen, then draw some bug Charge minions and use the regular Aviana+Kun combo to deal 30 damage. It’s not conventional but it is fun.