"Life and death form an endless cycle of reincarnation?"
If souls were the foundation of this world, then reincarnation was its most basic precept. The living were the living while the dead would enter the cycle of reincarnation to reinvigorate this world.
That was why it was a huge taboo to create a life that wouldn't enter the cycle of reincarnation; don't even mention personally breaking the cycle of reincarnation or making the dead come alive again. That was why I had never heard of anything related to resurrection magic in all the years I have been around—not even the basic idea of how it could be done.
No matter how ambitious and arrogant Emperor Yongye was back in the day, even he knew that there were some areas he must tread with caution. In the end, he only broke the taboo regarding Lisa, which still caused Ayer to come looking for him.