Gnar's Boulder Toss
is insane, not because of the damage, but because it is almost impossible to miss it (except if the enemy has a dash or uses flash), skill shots are usually about counterplay, but this skillshot consumes no mana, has great poke potential, deals insane damage AND THE MISSILE AREA AND SPEED IS JUST TOO GOOD.
To make it short, make it require more skill, it is already annoying to figth such an abusive champ in the toplane.
FOR THE SAKE OF COUNTERPLAY.