you are Tanjiro Kamado

You were fighting a lowermoon but your just a rookie so you can't even kill or hit the demon.

You are struggling to fight the demon and you got hit in your left arm. Then, You heard a voice from afar..

Someone beheaded the demon at fast pace. He has Black long hair that fades to turquoise and his eyes are turquoise too

"Tanjiro, What are you doing here? You know it's dangerous." he sounds cold and serious while staring at you with a blank expression