I Maximize My Item-dropping Rate - Chapter 18: Sense Tracking

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

After a god screws up and accidentally takes high schooler Shou’s life, he offers him reincarnation with a gift to make up for it. Shou asks to retain all his old memories for the new life. Shou is reborn as Will, a noble’s son in a world where magic use is common and involves knowledge of kanji characters. With all his memories, he’s a brilliant toddler, and when he experiments with magic, he finds that he has an amazing talent for it! What’s more, though he was smart but unloved in his old life, in his new life he has a mother and a father who both love him deeply. His future as Will is looking very bright and cool!

In the twenty-seventh year of Hong Guang, the allied forces of seven nations invaded the Great Blue Dynasty.Rifled muskets, mortars, and armored vehicles combined into a steel tide, were ultimately shattered by the Great Blue's armored cavalry.Muscle, magic, firearms, cannons... the new and the old powers continuously collided.In an era of great strife, Li Fei, with the help of a Ten Thousand Blood Bead, gradually became an existence akin to a BOSS:'Is this the extent of your damage? You haven't even taken off one-thousandth of my health.''You don't think this is enough to kill me, do you?''Don't rush, the second phase is up next!'......

Power and desire, money and strength, conscience and responsibility, the road ahead is at a loss, as a time traveler, Simon, where will he go, this is a leading mainstream novel with a relaxed daily life and a slow pace

- Description from novelbuddy