Fate/Stay Night: Unlimited Blade Works

[Kraco]

I didn't like the ending *that* much... the reason for that is that Shiroe will end up as Archer no matter what. We see him throwing his life away. Sure, it's nice that despite all that'll happen to him, "he still believes in what is right", but other than "Durr, I wanna be the hero" we get nothing out of him as to why he decides to go through hell instead of a heavenly life with Rin (she failed to stop him btw :/).

You are forgetting we are talking about mages here, not some white collar office workers. In the Nasuverse, and many others, mages are people who are single-mindedly chasing some goal or ideal. The whole Grail war itself was such a thing for the Einzbern and a path to it for the other participants. For both Emiya it's the hero business. Rin is actually a sad mage as long as she doesn't have a goal, unless saving Archer Shirou really is her goal. If you take that goal, that dream, away from a mage, you don't get a winner, you get the biggest loser.

Well, maybe he does that because now he can say "I was not wrong" after everything he said to Archer in the end, right? Pah...

Now he simply knows it's a foolish goal after Archer's lecture, but it's still what he's living for as a mage, nonetheless. With Rin around, as a man he has also other responsibilities now.

Now that I think about it, the saddest part about it is that, sooner or later, Rin will end up alone as a Clock Tower mage. She basically said so herself when she mentioned that she'll end her journey there, marking the end of their relationship before it even began.

She'll just spend alone the times Shirou is out there saving the world. But he'll always come back, no doubt about it. Give him a child and he'll come back all the more frequently and quickly. He's in love with her, after all. It seems unlikely he would neglect his own child when he practically worshipped Kiritsugu as his own sorcerous father figure. I reckon as a mage she would even appreciate some time alone every now and then, to advance her research in peace.