MTL - The Fallen Merman - ~ The past of the magician: I'm so annoying

Identity background: Fifteen years old, biological mother died, father unknown, holding a large legacy, poor performance in entrance examination, please choose a guardian.
↓
Candidate one: birth mother’s brother, not close, but eloquent, very gentle, reliable and sincere.
Option two: The eldest son of the father who has never been seen. His occupation is unknown. His age is unknown. Nothing is known.
In the last life, Yu Shulin chose his uncle, his mother’s funeral was all done by him, and he promised to take good care of him.
The selection is completed, and the result is being read …
After the choice was made, open the [pit you pit you pit you till you die] ending, please accept.
Yu Shulin, who was counted by his uncle’s family for his inheritance, was eventually released from prison, but immediately got killed …
@ # ￥% & * …… Restore the file.
Identity background: Fifteen years old, biological mother died, father unknown, holding a large legacy, poor performance in entrance examination, please choose a guardian
↓
Candidate one: birth mother’s brother, not close, but eloquent, very gentle, reliable and sincere.
Option two: The eldest son of the father who has never been seen. His occupation is unknown. His age is unknown. Nothing is known.
After the rebirth, Yu Shulin, whose negative energy exploded, said to hell and chose option 2!
The selection is completed, and the result is being read …
After reading the results, open the ending of [Just want to love you with the overbearing film emperor], please accept.
Yu Shulin, who was captive and was boiled like a frog in warm water: (╯ ‵ □ ′) ╯︵┻─┻WTF!

- Description from Novelupdates

# RELAXED # INFINITEDivine-grade Decomposition and Reconstruction System: This allows the user to decompose any object and reconstruct them.…A scraped car? I’ll just disassemble it and make it into a brand new expensive luxury car!A bunch of small diamonds? I’ll just turn them into a 10-carat giant diamond!An old phone? I’ll just make a futuristic phone that won’t appear for another 70 years!”What? Did I get sick? Simple! I’ll just gather a bunch of drugs, decompose them, and make a super medicine out of them!…A few years later, Augmented Reality, the Automated Electronic Management System, air-powered vehicles, humanity's first moon base, and other cutting-edge technologies were all created by a man who was once known as Dumb Lin.

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction.

As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!