This is a interesting piece of writing, @ppvicente. One of the goals every writer has is to be interesting. Goal achieved. The action is internal. We are in the mind, adopt the perspective of the narrator. Where is this person? A question that arises soon and holds us to the story as we seek an answer.
He is in prison. He has made the proverbial 'bargain with the devil'. He will fight in order avoid a worse fate.
This story is skillfully crafted. The format is untraditional. It's not clear if that formatting is intentional. In any case, the format helps to drive the story forward. (However the last sentence begs a capital on 'but'.)
Thank you for sharing this story with us. We are pleased you found a moment to exercise your creative self. Have you commented on the work of at least two other authors in the community? Thank you.