Parasite

You accidentally had an accident when entering an abandoned house, you fainted for a short time and almost died. During that period of time, a shiny black mucus approached your body and slowly penetrated your body through your skin and began to restore your severely injured body and almost revived you with How to recover all injuries from mild like skin wounds to severe like broken ribs and broken liver, lungs...
It is an unknown alien creature, it has just quietly come to earth and immediately recognizes you as its owner.
Its power is very terrible, teleporting, copying, creating objects (and living creatures but not arbitrarily)... It is parasitic but does not need to rely on the host to live but also has can help the host become immortal and protect the host's body absolutely.