I've heard that ost before. Actually I have seen the anime Mai-Hime a long time ago. Anyways, that is a good OST. However if I am not wrong, that OST is actually from Kara no Kyoukai movie series. Which I enjoyed alot!
As for the one I posted. That's one of the many theme songs for my class :D
And yeah. Lancer hasn't had the best luck in most of the routes, or perhaps in all.