I think it is:
subject 16 of the game assassin's creed II (haven't finished the game yet, so not sure if all lines are correct)
My mind is hazy, I'm completely stunned
being to long in the animus has bad effects on your mind and health
Is it seriously dangerous - should I run?
trying to escape from absergo
What day is it? What month? What year?
he's so long in the animus that his memories become twisted in past, present and future
Is it night so soon filled with shadows I fear?
in the end he was completely mad
Take heed! Beware! My brother, my friend
he warns the player, his "assassin brother"
I paid the price so you can see the journey's end
subject 16 died in the animus, but he left clues so you might get to the end
Cause its all the same - all but one affair
getting Eden's Apple and the power with it
Should I tell you the truth or do I lie?
subject 16 left a trail of clues to find the truth.
A most dangerous game
trying to find and get the Eden's Apple