[Takemi_Ikazuchi]

Archer lost a lot

Spoiler:

He failed to save Ilya
He failed to save Saber
It implies he had to kill Sakura
Rin became a fellow ally in his ideal of justice, but the game implies she died fighting the good fight. Yeah, she got infected by his ideals >_<

As for Shirou's future

Spoiler:

Hollow Atraxia shows that he will continue his path and eventually partner up with Rin's nemesis (out of all people) as his official working partner 2 years from now. However, this is just one of the possible futures.

Though, who wouldn't want to see that animated?