The spirit only kills nothing more. Once held by it you are a prisoner for life. So that’s a sad truth about being Rando. It is just full of pain and suffering. His life is now among the creatures called the others. He has been taken. All he does is just self inflicted wounds for him, or becoming the others. Instinctively however, he is just trying to rendezvous with Melanie the only other living person on board. See humans reach out for other humans. This is what Rando discovers while his conflict with them. Nothing else matters other than, that in the face of evil, we tend to reach out to the only other human face than him.