The one where Subaru finds out every time he dies, a parallel world is created. Scenes such as after he slit his throat are shown.
Arc 4, Phase 2 or 4? All the chapters are linked into PDF. Chapter index is slightly different in table of contents.
If I’m not wrong he doesn’t find this out, it is only one of the possible explanations and it’s not clear if those are parallel universes or just a simulation of sorts of what would happen if time moved on. That means we don’t know the nature of his power, if it is switching timelines or rewinding time.