One knows he is the protagonist without being told. No, you don’t have to be the protagonist even at the spin-off….
Regarding his personality, please refer to the original works like Fate and let me escape. The real image of Shirou is inside everyone’s hearts.
Based on that, someone who is Shirou and is not Shirou. Due to a certain fate, even in this world he lost his family in a certain disaster, and became Kiritsugu’s foster child. A hero of justice that saved him on the verge of death. That scene is burned into Shirou’s memories even now, but actually, whether the expression that Kiritsugu put on was real or not is on the verge of the questionable.
The reason why he didn’t become a robot that imitates Kiritsugu is largely Miyu’s existence, as expected. The extraordinarily large, righteous, and distant wish of saving all humanity. The grand dream of wanting to save everyone lies in his chest, but what lies before himself as the reality is the tiny protégée that only he can save. That time of contradiction and conflict took five years to melt the heart of tinplate.
Shirou’s story somehow or other had only the setting since the beginning of the serialization, but there weren’t any plans at all to have it drawn. However, at the time I wanted to delve into Miyu’s surroundings as the series continued, I immediately resolved myself and told me at last that I had to draw it. And when I actually tried drawing it, this is quite the… It fits quite well shonen manga-wise. It fits so well it’s amazing. That’s going to make Illya-san cry too.