In Unlimited Blade Works, why did Caster try to kill Shirou when she hadn't retrieved his Command Seals yet? I've been watching the UBW series. When Caster abducts Shirou to take his Command Seals so she can use Saber against Berserker, Archer comes in and saves him - then fights Caster.

At some point during the fight, Caster sees Shirou unprotected, so she fires at him (at which point Archer saves him again).



Why did Caster shoot Shirou, if she hadn't retrieved his Command Seals yet?

It's not like Shirou was any sort of threat. Surely dealing with Archer first would be a better idea, then retrieve the Command Seals off Shirou (since he's no match against Caster) to be able to fight Berserker using Saber.

Caster was definitely aiming to kill - other than the fact that her attacks literally blow up the ground, she was also smiling (as in, "gotcha!"), and then was surprised to see Shirou still alive.
This answer is based purely on speculation.

However, I believe that there is one reason for Caster to do that, and one reason why that is probably not a big deal to her.


First, Archer was called there in order to save Shirou from Caster. Targeting Shirou would force Archer to move in order to protect him. That kind of tactic is also shown in Episode 15 when


   Near the end of the fight, Gilgamesh targeted Ilya to force Berserker to backtrack and protect her.

Second, even if Shirou had been hit, she would probably still have been able to extract his Command Seals. (Note that she only makes one magical shot on Shirou's location)


The scene happens a bit differently in the VN. In it, the relative locations of Shirou, Caster and Archer are less clear - the only clear things are that Shirou is in the line of fire, and Archer has to backtrack from the temple's exit to reach Shirou. In particular, it is hard to tell whether Caster specifically targeted Shirou or if she was just shooting at the area.