The story about Obito becoming the spirit behind Kakashi after being crushed by a boulder at Kannabi Bridge. After the Fourth World War, Obito passed through the small soil, and he became one body with two souls. No one else could see it, only Kakashi could see it. It was probably the story of Coconut and Bamboo Shoots being reborn and joining forces to create Black Zetsu.
I'll write about it later. The author has a lot of ideas.
Concept: Coconut, coconut and bamboo shoots save the world