Skyshaker

Nurture 4 (Tap any number of creatures you
control with total power 4 or more:
put a level-up counter on this creature.
Nurture only as a sorcery).
Level 1-3: 4/6 Reach
Level 4+: 6/8 Reach,
When Skyshaker attacks, you may have it fight
target creature with flying.