The manga is about an MC that doesn't get bless by normal magic I forgot what his magic is all about but he invents a lot of things likes golems and such for the military eventually the military sends one of their famous woman general who's mana organ is already broken to be engaged to the MC. There's an arc where MC cures the mana organs of veteran soldiers who was wounded in the war and eventually MC also cures his fiancee and eventually they got married. There's also a chapter where MC creates a train.

Isekai De Uwamae Hanete Ikiteiku Saisei Mahotsukai No Yuru Fuwa Jinzai Haken Seikatsu

~4400 manga completed
~1700 ongoing...