The risk of an ordinary bloodline being transplanted into a royal bloodline was too high. It had a high chance fail of failure, not to mention creating a Saint Child.
It was likely that before the experiment was completed, a monster would be created.
Under such circumstances, if one wanted to complete the experiment, there was only one way. That was to improve the quality of the experiment itself.
Originally, the experiment was only conducted with some low-level bloodlines, but now it was conducted directly with the direct descendants of the royal family, so the effect was naturally much better.
It was just that ordinary experiment subjects were easy to find, and there were many experiment subjects that were willing to join in order to change their lives. However, royal bloodline experiment subjects were very difficult to find.