Behind the Scenes of Ultra: Starting from Making a Doppelgänger

[Villain: The protagonist is not a good person, enter with caution] I just took a nap, but inexplicably traveled to the Ultra World. What kind of system is behind the scenes? Can you use various materials to create clones? Jie Jie Jie! (This book was written before and I was not very experienced at that time. There were still many typos. Now I have changed it and welcome everyone to try it.)