300年引きこもり、作り続けてしまった骨董品《魔導具》が、軒並みチート級の魔導具だった件

Synopsis

So I continued to stay shut-in for... Huh? 300 years?! One day, a high elf named Edson realized this astonishing truth. Absorbed in his magic tool research, he felt that he had subconsciously let 3 years pass... but in fact, it has been 300 years! Edson decides to go outside and find out what happened to the outside world, now that 300 years have passed. However, even after 300 years, magic tool technology had not advanced; and even the junk among his magic tools are being treated as cheat-level tools!?