Anime Crossover: I Slaughtered Muzan from the Start, Then Killed Gion

[Simulator] + [Invincible Protagonist] + [Swordsmanship]

P.S. Momousagi fans and holier-than-thou types, stay away. If you like romance and harem elements, stay away too. The protagonist is only interested in swords, not women.

Reborn in the world of One Piece, Luo Qiong watches countless Marines and pirates engage in a bloody slaughter across the frozen sea. He realizes this is the Paramount War.

When he sees a tall, handsome man wielding a gigantic black blade slash in his direction, sending a sword wave hundreds of meters long, all he feels is despair...

[The Crossover Simulator is at your service. You currently have one simulation chance. Begin simulation?]

With his life on the line, Luo Qiong has no choice but to begin the simulation.

[Randomly selecting a simulation world...]

[Randomly selecting a talent...]

[Congratulations, you have arrived in the world of Demon Slayer]

[Congratulations, you have successfully drawn a talent!]

[You have obtained the gold-tier talent: Born Sword Prodigy]

[Gold-Tier Talent: Born Sword Prodigy. Any sword technique below gold quality can be learned at a glance and mastered to LV.20 with a single practice. The swordsmanship level cap is increased by 30, and the proficiency required to practice sword techniques is greatly reduced.]

Luo Qiong grins. He’s about to become invincible.

(The main world in the early and middle stages is One Piece. The simulator worlds appear in this order: Demon Slayer, Sword of Yanhuang (original, ongoing), A Certain Scientific Railgun, Jujutsu Kaisen, One-Punch Man, Bleach, Sword Art Online. Original worlds will also be mixed in.)