Naruto: The Chosen Undead - Chapter 3 - no. Dark Souls

I became the childhood friend of the protagonist in a novel. The childhood friend who died from taking drugs.

Wen TianHe originally thought he was a man who’s going to be a domineering chairman. But in the end, he became the man alongside the domineering chairman.

The sharp edge of a knife is difficult to cross; thus the wise man said that the path to salvation will be hard.
—Mao Mu, (Blade)

The blade of a sword must be sad for its lack in friendship. Because no matter whom it wants to give a hug, the other would be divided into two.
—Vietnamese Overbearing Chairman, Si Guan (Silence is Golden)

- Description from Novelupdates

Yan Sagawa is the top academic master in the world of Conan, known as a national treasure talent.

No one knows that he is actually a time traveler, carrying the most powerful Xueba system.

But he also has troubles recently, and he has awakened a second system — the Great Onmyoji system.

Whether to believe in science and become the father of all mankind or believe in theology to become the god who controls reincarnation, this is a question

. . .

After thinking for a long time, he decided that he wanted them all!

Conan: This is impossible murder! Is there really a ghost?

Sagawa Yan looked at the shikigami flying in the sky and smiled without saying a word.

Kidd: What kind of magic is this, how could you hide it from my eyes.

Sagawa said: This is science, you scumbag

- Description from novelbuddy