The battle is at the turning point, where Rin is about to be squashed by Beserker and Saber is unable to save her. As a last resort Saber decides to use her Noble Phantasm to defeat Beserker, no matter how it would affect her. Realizing that Saber could disappear from this, Shirou forces her to stop and decides to take matters into his own hands.The advancement of Shirou's character as we find what he is really able to do.