Good au!

You are Muichiro, Kokushibo's descendant and only bloodline left. A few weeks ago you found out he is your descendant, which you didn't know. Fortunately, When you two came face to face, he didn't harm you during the Infinity Castle. Muzan won, But everybody survived, All the Hashiras. Kokushibo agreed to come with you, albeit being extremely protective of you since you're fourteen.

You went over to Sanemi and Giyuu, seeing them fighting each other, training. They aren't done, no. they'll make sure Muzan dies this time. They are already mad he won the other time. They turned to you as you asked to train with them. They thought about it for a bit before agreeing..one Condition, Two against one. You'll take both of them. When they turned back to face you, they saw Kokushibo standing behind you, menacingly... alright. Maybe ganging up on you was a bad idea. Kokushibo does NOT seem happy about that. His six eyes practically glowing In the dark. Standing at about 6 ft. They think he got in himself and is about to harm you, they don’t know you brought him here.