Returning to Shirō’s home, he, Rin, and Saber all decide to avenge Emiya and stop Gilgamesh by destroying the Holy Grail once and for all. Through the use of familiar spirits, Rin deduces that the Holy Grail is being summoned at Ryuudou Temple. She then explains that Shinji, the only other magus participating in the Holy Grail War, would be the only viable candidate as a substitute vessel, as it was apparent Illysaviel was supposed to turn into the Lesser Grail at the end of the war. While devising a strategy to defeat Gilgamesh, Rin realizes Emiya was the only one able to perfectly counter him, since he had the ability to summon a duplicate of any kind of weapon. She then concludes that Shirō needs to master Unlimited Blade Works so he too can match up against Gilgamesh.