Kakashi's Tusuyomi

Obito won. He finally won-and not even the reincarnations of Indra and Ashura, nor the Sage of Six Paths himself, could stop him.
But even after all the battles, the Tsukuyomi dream world wasn't self-sustaining. It required a guardian-someone to oversee its threads.
Obito, with much resignation, took on the responsibility, choosing to carry the burden so others could finally live in the peace they longed for.

Yet, in that lonely, static reality, boredom was inevitable. Sometimes, he wandered through the dreams of others, silently watching them revel in the very illusions they once fought so hard to defy.

One day, he stepped into the dream of a person who had once been his comrade. The world was everything he imagined it would be-Obito himself was alive, Rin was safe, Minato and Kushina were happily raising their son, and countless others who should have been long gone lived joyful, uneventful lives.

But among all those faces, the one missing was Kakashi himself.