Light and Darkness of the Grail

Grand Order was founded to travel within different time eras and grain all the piece of grails to become one. Within the Holy Grail Wars and fixing the time eras, one world with an interesting time era comes into a dark mind to gain the full Greater Holy Grail, but only one can stop the darkness form and that was by the light of a pure hero with hope in his heart. Naruto/OC x Harem