MTL - There’s Something Wrong with this Development! - Chapter 30

Super soldier Su Chen, returned to the city and returned to the city, set off all directions! The king of soldiers that once famous the world, let everyone be convinced!

- Description from xbiquge

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

Reborn as a sword, he lived for hundreds of years, and then he occupied the body of a 15-year-old prince.

Anyone who could construct a stable Spell Model could become a Wizard — that was the Wizards’ ultimate secret! Having been given a new life as the son of an aristocrat and armed with a super quantum computer from his past life, Spell Models came as easily as breathing to Merlin. With this overwhelmingly huge advantage, would Merlin become the greatest Grand Wizard of all time?

- Description from Novelupdates