Shirou, the Seeker of Darkness

A proper Fate stay night kingdom hearts crossover. Shirou becomes a human Heartless and speaks like Ansem, Xemnas, Xehanort. Kingdom Hearts is simply another word for the Swirl of the Root, Akasha; one only known by the Realm of Darkness. Shirou searches for Seven Princesses of Heart during the Fifth Holy Grail War in order to reach it. Shirou/Sakura, later Harem. Saber Alter used