Toaru Hikuushi e no Tsuioku - Chapter 3

Vincent Strider was a gun for hire who made a living by killing whoever it was his clients wanted dead. But during one mission, he died in a fierce gunfight. However, death was not the end for him. Vincent found himself reincarnated in another world, facing a floating interface that flickered before his eyes.[Synchronizing Host!][Military System initializing.]Vincent found out that in this system he received, he can summon soldiers, tanks, aircrafts, and even warships! This is going to be exhilarating.

I used a cheat to devise a character in a game. Upon regaining consciousness after pressing the play button, I discovered myself embodying the character I had crafted, the ‘Priest of Corruption.’ This character was intentionally created with unfavourable statistics and is widely detested! The sole item in my inventory was the withered hand of a woman, yet could it possibly be the hand of a goddess?

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates