Willow Dale, Sun's Daughter

Haste, Trample
Willow enters the battlefield with four Charge Counters.
Whenever Willow untaps, you may pay {x} to put
that many Charge Counters on her plus one.
Remove X Charge Counters from Willow: Willow
gains +X/+X until the end of the turn.
When she leaves the battlefield, deal Y damage
to all creatures, Planeswalkers, and opponents,
where Y is the number of Charge Counters she
had.