Where Is the Devil?

[No system, daily life in the early stage, overthrowing the old society in the mid-term, and saving the doomsday in the later stage] "Brave young man, go and save the other world ruled by the Demon King!" Lauren received the blessing of the Goddess of Fire and became proficient in almost all fire magic. However, everyone in the other world told him that the Demon King did not exist! What's even more strange is that with his terrifying strength, he can't find a formal job. "With no family background, no recommendation from a mentor, or even a decent mentor like you, I'm afraid it will be difficult for you to adapt to the mage group." It takes ten years for the Adventurers Guild to wait in line for a slot! The competition for positions in the Royal Mage Corps is one thousand three to one! You actually deliberately conceal your own value!