Grinding EXP From Fireball Skill

Is it hard to become a mage? Are those who master magic truly one in ten thousand? Just grind it out!!! Minor Fireball, Fireball, Greater Fireball, Explosive Fireball, Chain Fireball, Meteor Fireball… Great Sun Nuclear Blast! Novice Apprentice, Mage Apprentice, Novice Mage, Mage, Archmage, Legendary Mage, Saint Mage… God of Magic! …… “Wait, am I already invincible?”