You are an immortal stuck in the same body that you are right now. Limited to its own ability and base stats. Nothing more nothing less. You cannot be felled or be found dead. Still susceptible to diseases but none will be able to kill you. Can be destroyed shot at torn to shreds or burnt but you will come back either way as your body is reformed. Just remember you will feel everything, but you will lose a random memory every time your body fixes it self. Nothing can kill you and you cannot will yourself to death. You are stuck in this eternal prison that is your body.

The second option is that you can prolong your life by taking the life of another. But the amount of life you can get is dependent on how close that person is to you. Also for every use you increase your lifespan the next time you do it, you need more to increase your lifespan by the same amount. You're basic stats increase as you are able to merge the personality and body of those who you kill into yourself. You can still be killed remember that.