Hero of Leina Tower
Creature — Human Warrior
Heroic — Whenever you cast a spell that targets Hero of Leina Tower, you may pay 
. If you do, put X +1/+1 counters on Hero of Leina Tower.
"You cannot achieve greatness if its seed has not already been planted in your heart."
Illustrated by
Born of the Gods#123RareEnglishLegality
Rulings
Heroic abilities will resolve before the spell that caused them to trigger.
Heroic abilities will trigger only once per spell, even if that spell targets the creature with the heroic ability multiple times.
Heroic abilities won’t trigger when a copy of a spell is created on the stack or when a spell’s targets are changed to include a creature with a heroic ability.
The amount to pay for is chosen as the triggered ability resolves. No player may take actions between the time you pay and the time Hero of Leina Tower has X +1/+1 counters on it.