When searching for the container of the Kyuubi, Itachi discovered a shard of the Soul Edge that took him to 16th Century Europe where he got mixed up in the war of the Soul swords. After awhile, Itachi encountered Nightmare and Tira that caused him to go insearch of the Soul Edge to give to the Akatsuki and he obtained the Soul Calibur by killing Siegfried then the Soul Calibur became a Ninjato version of itself. At the end of the fanfic, Nightmare used to the Gem of Helios to copy the Sharingan from Itachi's body into himself and the Soul Edge, which turned Nightmare into Akumu Uchiha but was quickly defeated by Itachi and the Soul Edge was destroyed then Itachi returned to his era with a knocked out Tira.