Picking Androxus is a good idea to counter willo
Her seedling with legend card can do 4250 if you use reversal you can do 4250x0.75=3187.5(more than her maximum health)
It's difficult for she to hit you while flying
When Willo Ults, fly into the air as well to take her down. This makes it a lot harder for her to hit you, especially if you have good aerial movement.