Archer really has a bone to pick with Shirou…
As mentioned last week, the connection between Shirou and Archer is pretty clear at this point. Both him and Shirou shared the same dream of wanting to become a hero. Unfortunately, he has already achieved that and it has caused him nothing but pain and regret. Once that line was said, it seems like Saber realized who exactly she was talking to.
He’s set on stopping himself from going down the same path that he walked. Shirou is the type of person who would stick to his ideals, no matter what. He’s set on living solely for others, and has no real desires of his own aside from that. Archer lived his life the same way, and in the end he was worked to the bone. He was nothing more than a weapon for others, who used him to fight for their own purposes.
While all of this chaos is going on, Rin and Saber form a new master servant pact. In terms of ability to control mana, Rin is probably much better suited to handle someone of Saber’s caliber. Rin also originally wanted to summon Saber, but now that has become a reality.
Archer decides to reveal his true nature to everyone so that they can understand why he’s the way that he is. He’s not really an archer, nor a swordsman, but rather a magus. He was a man who fought for his ideals as well, and all that he had left in the end was this desecrated wasteland.
It seems like Archer is reaching the final stages of his plan. He was a lot kinder to Shirou earlier on in the series, but now that the clock is ticking, he’s done playing around. He kind of gave Shirou a chance to grow, but now that he’s on the verge of disappearing, he’s finishing what he came to do. Using Rin as a hostage, Shirou has no choice but to confront him before his time is up.
Rin’s dream sequence basically paints the picture of what happened in Archer’s life. He lived for others, fighting for justice. He convinced himself that it was his purpose. As long as other people were happy, he could be happy. He literally lived for others. He became a heroic spirit in order to continue serving other people, even after his death. In the end, it seems like he was only summoned to continue fighting for others, and causing death and destruction. His original ideal was to always protect and save others, but it’s an impossible ideal to strive for. His ideal completely betrayed him, and he’s stuck forever in this loop which is why he was summoned into this holy grail war, to free himself from it.
Even after all of this, Archer is still a man of his word. He’s willing to uphold his agreement with Shirou. In the past too, he showed some restraint when it came to dealing with Shirou. He’s had opportunities to kill him, but instead he even helped Shirou when his magic circuits were causing him problems. Even if his ideals have betrayed him, there might be a shred of him that still wants to believe.
Archer’s time is limited so he has to make his decision now. Whether he can truly bring himself to kill his past self is still up in the air. Shirou also has to have a moment of reflection after seeing the type of person he will become if he continues down this path. At the end, all remaining participants are gathering in Illya’s castle for a massive showdown.
You can watch Fate Stay Night UBW Episode 18 on Crunchyroll