Class for All: I'm a Mage, and I Only Have Super-Tier Skills

[Invincible power fantasy + class awakening for all + showing off + no playing the pig to eat the tiger + no need to think too hard + no System.] Blue Star was invaded by the civilization of the gods, leaving the entire planet desolate and bleak. Crops yielded no food, and the only way to survive was to earn rewards on the Battlefield of the Gods. Countless people on Blue Star hoped to awaken their own classes and enter the Battlefield of the Gods to earn rewards. Chen Yuan, who had just died, transmigrated into the body of someone identical to him. At the same time, he awakened a class and became an outstanding “Archmage.” He thought being a mage was already a pretty sweet deal. But when he looked at his talent, he was stunned. “My talent seems just a tiny bit overpowered?!” The first time he uses a different skill each day, it’s guaranteed to become an upper-tier skill?? A fireball turns into a colossal Flame Emperor? An ordinary water spell becomes an endless tsunami? I only added points to my movement speed, so why do I have a Mach cone?! But things weren’t that simple. As Chen Yuan leveled up and grew stronger, he gained even more outrageous talents. Ignore skill cooldowns, learn an unlimited number of skills, and automatically upgrade skills into forbidden-tier spells... That day, countless people stared at a fireball as immense as the sun and were left speechless. We’re all low-star mages, so why is the gap between us so huge? [The blurb can’t do it justice. Please read the story.] [Also known as: You’re Annoying Me, So Is There a Problem with Opening with an Upper-Tier Skill? I Told You to Use Skills, Not Unleash Your Ultimate! Sorry, I Only Have Upper-Tier Skills to Open With]