Me, Destroying Everything All Alone

[Dark, niche, ensemble cast, not a power fantasy, bleak, light novel. All right, that's a full stack of warnings.]

As a person, I think my life should be an exam paper worth at least eighty points.

But my future self has become obsessed with me.

He is utterly alone, yet driven by a mission.

Little by little, he draws himself into a world on the brink of destruction.

Save the world, or save myself?

No. I'm just destroying everything on my own.