I believe it is Strange Girl by Hitomi Kuroishi. I did a bit of research and reverse audio searching and eventually ended up in a wikipedia article which seemed to confirm this. I found the song so you can double check it in case I got the wrong music accidentally.
Answer separated from question
I FOUND IT ON YOUTUBE! Sadly, it is unreleased and it's not the best quality. If there's a clean version anywhere that'd be awesome too. While I do have the actual audio of the track, it still has the voices and everything.
Heres the link https://www.youtube.com/watch?v=QVWyHqlTDDI&list=PLClDieKmym5Df7m7B3cF9z6ot1yNiq7X0&...
I have a theory about this.
The Geass consists in three stages:
Normal stage -> Lost control stage -> Both eyes stage.
The point with third stage is that, only in this stage, the user is able to complete his/her contract and become a Code. Lelouch and any other Geass' users will not show any difference in his/her power level or new abilities, since this ...