It laerns it at lv77, like ho-oh learns sacred fire at 77. Usually whirlwind is at lv77 and aeroblast is at lv1, but they switched.
"It all starts with this, a jewel containing the ultimate power." -Shadow "I still remember what I promised you, for the people of this planet. I promise you, REVENGE!" -
No one knows Shadow better than me. Or likes him more either. Go ahead, try me.