My Unique Skill Makes Me OP even at Level 1

After dying from overworking at a black company, Ryouta Satou found himself reincarnated in a new world. However, his level was restricted to 1 in this new existence. This inconvenience did not deter him from utilizing his unique skillset to create impossible items from monsters. As a result, he collected a vast array of weapons and gear that could only be wielded by himself. Additionally, he augmented his stats using special ability-up items. Despite only being level 1, Ryouta emerged as the most powerful character in the realm.