All-Cutting Jian: At the end, 自分 becomes his Sword/Light
At the final act: 自分 cuts not 相手, but The Void/虛 itself
Void Radiance Sword Art: Like a ray of light piercing the void, 自分's jian can cut/bathe All Planes of Existence in All-Cutting [Light]
[剮虛]: In an epiphany, 自分 learns that To Cut/剮虛 is not to cut one's foe, but to cut The Void/虛
Thus, in the final act, 自分 [Cuts], but not 相手, as 自分 completely transcends into another [realm], as 相手's presence's rendered utterly insignificant before him