My Invincible Soul Transmigrates to the Demon Slayer World

[Two male leads / No female leads / Not simply a story about the protagonist's strength / Ensemble cast / There are romance arcs, but they don't involve the protagonist]

Recommended for readers who've read the original or watched the anime. Some scenes will be skipped.

Chang'an Fengxing stayed up all night to clear all 200 cycles of Dark Souls, then finished the final volume of Demon Slayer. Swept away by a flash of white light, he woke in another world as the mysterious traveler Tanjiro had rescued from the snow.

The Soul God System activated, awakening the Lord of Cinder's legacy, Elden Lord's authority, and the skills of legendary hunters! Armed with the Mortal Blade Kusabimaru and countless Soulsborne weapons, he can fuse the Golden Order with the Frenzied Flame to create a Breathing Style all his own.

He joins the Demon Slayer Corps and slays four Lower Ranks in a single month, setting a record for becoming a Hashira faster than anyone before him and earning the title of Hashira of Law, feared by the other eight Hashira!

He rushes to the Mugen Train to aid Kyojuro Rengoku, rewriting the Flame Hashira's fate. In the Entertainment District, he joins forces with the Sound Hashira and crushes Upper Rank Six. At Swordsmith Village, he witnesses Nezuko conquer the sunlight and helps everyone surpass their limits. To verify Sun Breathing, he even transmigrates back to the Sengoku era!

The Twelve Kizuki become little more than experience fodder beneath his blade, and Muzan's thousand-year reign teeters on the brink of collapse. When a Soulsborne powerhouse arrives in the Demon Slayer world, Chang'an Fengxing stands with his sword in hand. “My blade slays demons and protects the people. I'll rewrite the ending of this world!”

(Note: Sekiro isn't a Soulsborne game, but since it mainly uses a Japanese sword, Sekiro's skills and sword techniques will be the protagonist's main fighting style.)

(Also, many of the settings are my own creations, such as the Holy attribute, which is more effective against demons than Nichirin Blades. Please just take them as they are.)