In Code Geass R2, episode 14, at time code 14:35, there is a track playing. It plays after Rolo kills the other children with Geass. The battle between Lelouch, Jeremiah, and V.V.
What is the title of this track?
I have checked all soundtracks; it has not been released. People on anime forums confirm that (for example, here: http://forums.animesuki.com/archive/index.php/t-38178-p-4.html).
The only one is someone's edit here.
It's an unreleased piece from the soundtrack called Collective Subconscious. You can find it here: