[Darknemo2000]

If you are asking about Novels then

Spoiler for Saito and elf in novels:

Tiffania found him lying and brought him in... It took few weeks till he was able to walk again not to mention that he also lost all his powers thus considered himself useless for Louise and didnt tried to contact her. While Louise tried different ways to find him but it all failed as Saito lost his powers... She even found his torn jacket. Siesta broke at the view but Louise was already mature enough to still have hope (well before that she had it bad though, and her suicide attempt reflected that). And indeed finally she met him after being saved by Saito from Sheffield. And then that erotic night in bed followed...

Well anyway, Saito escaped more or less (with a help of Derflinger) but didnt had any strength and would have died... In a sense he really died as he lost all his powers. But since Louise kissed him once they met he got his powers back again.