Extraction and Body reconstruction system

A sickly boy dies and Chāng Haoyu from earth invades his body. He obtains a system that can extract power from artifacts, plants, and even corpses.

I was given a system that can give me the powers of others so long as I can get their items or corpses, with a system like this being a villain is only natural, and since it was given to me, what type of person would I be if I didn't use it to the fullest?