Demon Slayer: You can become stronger by swinging your sword

No heroine + anime + passion + system + time travel
Traveled to the world of Demon Slayer, and was accidentally bound to a system that requires drawing the sword 1 million times to become stronger...
"Swing the sword + 1"
"Swing the sword + 1"
...
Many years later,
A blood-red Nichirin sword was placed on Muzan's neck
"Brother Muzan, the sun is so nice today, do you want to go out and bask in the sun together?"
[Demon Slayer + Ghoul]