Ep 5. The Dark Sword Bares Its Fangs

Shirou and Rin are trapped in Archer's reality marble, Unlimited Blade Works, facing a horde of powerful swords. As they struggle to find a way out, Archer taunts Shirou about his ideal of becoming a hero of justice and how it is a foolish dream. Meanwhile, Saber and Lancer continue their battle outside, with Saber struggling to keep up with Lancer's incredible speed and agility.

Back inside Unlimited Blade Works, Rin and Shirou are forced to fight off wave after wave of swords. Rin uses her magecraft to create magical barriers and projectiles, while Shirou focuses on projecting swords of his own. They come up with a plan to take down Archer, but it requires Shirou to use his risky reality marble projection technique.

Outside, Saber is finally able to land a hit on Lancer, but he manages to use his Noble Phantasm to escape and attack from a distance. Saber realizes that she won't be able to win in a straightforward battle and decides to take a different approach.

Back inside Unlimited Blade Works, Shirou successfully uses his projection technique, creating an army of swords to overwhelm Archer. However, Archer isn't deterred and continues to taunt Shirou, telling him that his ideal is nothing but a trap. Shirou is shaken by Archer's words, but Rin encourages him to stay true to himself and his ideals.

Meanwhile, Saber uses her knowledge of Lancer's personality to bait him into a trap, but he is still able to evade her attacks. She decides to use her Noble Phantasm, Excalibur, but it requires her to use up all of her energy and leave her vulnerable. She charges up the attack, but just as she's about to unleash it, Lancer stabs her through the chest.

Back inside Unlimited Blade Works, Shirou and Archer engage in a final, desperate battle. Shirou is able to use his projection technique to create a sword powerful enough to pierce through Archer's defenses, but Archer doesn't give up. He reveals the truth about his identity and why he became a hero, leading to a shocking revelation for Shirou.

The episode ends with a tense cliffhanger, leaving viewers wondering what will happen next.