It could be possible in theory, but to actually perform something like this should be impossible.
To recreate cells and tissue while keeping the smallest microscopic details into mind was just too much, no matter how remarkable one's control over magic was.
"It's possible to create a body, but the hard part is inserting the soul back once someone dies. No one has ever been able to perform the magic of that level successfully."
"But how were you able to do this? To recreate the human body from scratch, you would need a phenomenal amount of control. And along with that, you would need extensive knowledge of the human body, down to the smallest details."
"The control that you speak of is something that I was born with. I can combine any and all elements out there, so it's not a big deal for me. And you don't need all the knowledge of the human body if you know how to use elements properly."