Amaterasu

Sasuke versus Itachi crosses from jutsu into mythology. Itachi's Tsukuyomi shatters against years of hatred, so the elder brother escalates to flesh and flame — and when Sasuke's grand counter, a sky-splitting Kirin carved from natural lightning, obliterates the hideout, Itachi walks out of the ruin wrapped in the Susanoo, the Mangekyou's final armor. Sasuke's reserves hit zero, and the thing he borrowed power from comes due: Orochimaru's white serpent erupts from the cursed seal, eight heads against a god in armor.