Rider and Archer had a drink before they fought. He asked Archer that since they both have very powerful Noble Phantasm, they should join forces to rule the world. But Archer replied that he only has one comrade he trust and there is no need for two kings.
After their drink, Rider activated his Noble Phantasm and ordered her troops to attack Archer. Kariya was hallucinating about Sakura and she asked why is he doing this. He claimed he was promised by Kirei that he will be offered the Holy Grail to save her. She asked if she will be able to see her mother again which freaked Kariya.
Saber was trying to avoid Berserker's long range rifles and finally used a truck as a decoy to attack him. But he was able to block her attack and she demanded the true name of Berserker.
He revealed his helmet and Saber was shocked that it was her former knight, Lancelot. She then realised what Rider had mentioned before-A king should not just save his people but must be able to lead them. Berserker was filled with rage and continued attacking Saber.
Archer used his Noble Phantasm, Sword of Eu and destroyed Rider's armies and the dimension space. Rider told Waver to live on and he charge towards Archer. However he was chained up before striking Archer and he stabbed him with Eu.
Rider then could hear the waves of Okeanos and died after that. Archer approached Waver and asked if he is Rider's master. He replied that he is now his follower and Rider's last order was him to live on. Archer was touched by Waver's loyalty and spared his life.
Emiya has arrived at the Public building where Kirei has placed Iris's body in an auditorium...
Rider is gone which means leaving three more servants to end the war. But I felt Rider's death was very emotional as he treated as a friend rather than a master and telling to live on to tell his story to future generations. The last scene of him hearing Okeanos was a sign of a dream he could never achieve however he has already touched Waver and even Archer of his greatness. I salute you, Rider!
Berserker's true identify as Lancelot wasn't really a surprise if you have been following the clues. Through I find him like a crazed dog battling Saber. Maybe in the next episode, we will get to know the reason between her and Lancelot's fallout. With Emiya rushing to confront Kirei, what will be the outcome in the end?