Starting with the Hashira Training Arc in Demon Slayer, I Become Muzan’s New Dad

[Lightning-fast pace, pure wish fulfillment, so satisfying it will blow your mind!] Lin Tian transmigrated into the world of Demon Slayer, only to find that the timeline was already nearing the end, in the Hashira Training arc. With the finale about to become the End of the Hashira, Lin Tian resolved to change everything. Fortunately, he awakened a God-Tier Trainer System. Whenever someone he trained made progress, he would receive a ten-thousandfold return. So he set his sights on Tanjiro, the protagonist of Demon Slayer… On the day of the final battle, Muzan watched the two of them wielding Sun Breathing and fell into deep thought… Lin Chuan: “If one isn't enough, then I'll bring in another. Muzan, prepare to die!”