No, this has nothing to do with Sean Bean, The Game of Thrones, or A Song of Ice and Fire; it’s a track from the anime adaptation of Tsubasa: Reservoir Chronicle (technically RESERVoir CHRoNiCLE, but even I have standards).
I haven’t watched it; I haven’t read the manga it was based on. Everything I know about it comes from the wikipedia page, which makes it sound like Tsubasa: Reservoir Chronicle is CLAMP’s Dark Tower series; characters and settings from their many other works are all tied together in a weird mishmash.
However, it does have music by the always excellent Yuki Kajiura, and so off to youtube to look for tracks I went.
This live arrangement lacks the chanting present in the orignal, but it’s still quite good.